BAUBLE-laden Christmas trees, jolly snowmen, beautifully wrapped gifts, delicious gingerbread houses, jaunty nutcrackers, cosy mittens, prancing reindeer and delicate flurries of snow. If flicking through the pages of Johanna Basford's intricate hand-drawn illustrations doesn't fill you with festive cheer, then perhaps like the Grinch, your heart may simply be two sizes too small.

For those unfamiliar with her work, Basford is a pioneer of the booming adult colouring book trend. The Aberdeenshire-based illustrator and self-dubbed ink evangelist published her first title, Secret Garden, in 2013. She has since gone on to publish four more – including Enchanted Forest, Magical Jungle and Lost Ocean – awakening a new genre and selling 20 million copies worldwide to date.

Her latest offering, Johanna's Christmas, is set to further stoke Basford's success in burning up the global bestseller lists. At a personal level, the 33-year-old hopes it will grow what she fondly describes as a mission to "make the world a happier and more creative place through colouring".

While that last sentence may have the cynics groaning inwardly, the sentiment is typical of Basford's infectious Pollyanna-esque enthusiasm. Put simply, she is a glass-half-full kind of gal: warm, delightful and utterly charming.

Christmas is still some weeks off when Basford's voice drifts down the line from her home in north-east Scotland where she lives with her husband James/Elvis (more about the name in minute), their two-year-old daughter Evie and a Labrador called Simcoe.

It has been a whirlwind few years for Basford with sales of colouring books aimed at stressed-out grown-ups rocketing. Waterstones reported a 300 per cent rise year-on-year between Christmas 2013 and 2014. Nielsen BookScan research, meanwhile, estimates that around 12 million were sold in 2015, a huge jump from the one million sold in the previous year.

Fans of the genre can be found scribbling away on trains, and in airport lounges or doctors' waiting rooms. There are meet-up groups at libraries and coffee shops, and online forums where tips are shared with completed pictures uploaded for critique (but mainly hearty praise).

Basford, who received an OBE at Buckingham Palace last week for services to art and entrepreneurship, was told by Prince William that his wife Kate, the Duchess of Cambridge, is a big fan of Secret Garden.

Even so, the extent of her meteoric rise has taken Basford by surprise. When she first pitched to publisher Laurence King in 2012, Basford thought it might be viewed as a "crazy idea". It doesn't seem crazy now.

"It was never my intention that it would be a commercial pursuit or something I thought I would make a lot of money from," she insists. "For me, it was a passion project that I was going to do in my spare time while I was working as a commercial illustrator to pay the bills.

"Colouring books for adults was just something I thought was a wonderful idea. I wanted to make something really beautiful and share it with the world. I hoped that a few other people would feel the same.

"I took a lot of advice when deciding whether or not to go for the project. Overwhelmingly the logical answer was: 'Don't be so silly. You could spend nine months making a book and only sell a handful of copies.' But when you have those ideas bubbling and you really believe in it and think it is a wonderful project, then you just have to go for it regardless of the practicalities."

That first book – Secret Garden – quickly racked up a million sales. "I had a much easier time convincing them to do the subsequent books after the first one," she chuckles.

To be fair, Basford doesn't seem overly fixated on the sales figures. "I think at a certain point the numbers just stop making any sense at all," she says. "Now I'm more overwhelmed when I go on social media and I see all the pictures people are uploading of their own colouring in, the amount of communications that we're getting and the feedback from the colouring community.

"That is easier for me to gauge because it is visual as opposed to seeing a number in an email or on a spreadsheet. In terms of the engagement and the amount of colouring that we see on social media it is really heart-warming and amazing."

There is something rather adorable about people colouring in her drawings and then proudly wanting to show Basford – the creator – the finished product. How does that feel? "Well, I think of the books as a collaboration rather than myself as the creator," she clarifies.

"It is just my job to do those black and white outlines, then whoever has the book brings the pictures to life with colour – they are really completing it. We work as a team.

"It is nice for me to see how those pictures end up because when I send away the art work or see a colouring book in black and white, to me it's then only half finished. It finishes off the process and resolves everything when I see the images start to appear in colour."

The idea of an adult colouring-in community would have seemed laughable a few years ago. Now it is a thriving and growing entity.

"I see the colouring books as a great digital detox, but social media has really helped foster that community," says Basford. "Sometimes in creative communities people can be quite guarded, they almost don't want to share their knowledge and keep everything a secret.

"Whereas with colouring-in you see the exact opposite: people want to post a YouTube tutorial with a new tip or let people know about a great bargain they have found on a certain brand of pencil. It is very collaborative. There is a sense of warmth and sharing."

She is reticent about taking credit for the popularity of the trend. Basford reckons the hobby has been an underground movement for years with people doing a spot of sneaky colouring-in to de-stress after putting the kids to bed.

The ease of accessibility, she adds, is undoubtedly a key element of its lure. "You don't need an easel, a 10-week block of night classes or expensive studio equipment. You just need a book and some pens or pencils. It is great way for people to tap into a sense of creativity and nostalgia. It is nice to forget about Brexit, the US election and just do a bit of colouring in."

With nature a strong theme running through her work, it's no surprise to learn Basford grew up in the countryside. "My mum and dad have a fish farm just north of Aberdeen in Auchnagatt," she says. "It was very free-range and organic, not a lot of TV and if you wanted to see mum and dad, well, you had to go out and help on the farm.

"My sister and I had that very rural childhood where you have to cultivate a wild imagination because there is not much else to do. There were dens, secret gardens and puddling about in the burn looking for tadpoles. Quite Enid Blyton now I think about it."

These days she lives close to Ellon ("just a few miles away from where I grew up") with James/Elvis Watt, co-founder of Scottish craft beer company BrewDog.

Watt, 34, and fellow brewery boss Martin Dickie legally changed their names to Elvis by deed poll in October after the late rock and roll legend's estate threatened legal action over their grapefruit and blood orange IPA called Elvis Juice.

The duo argued that the name "Elvis" is not exclusive, and in a bid to prove this, said they would thereon be known as Elvis Watt and Elvis Dickie.

There is a thinly veiled sigh from Basford when I mention the recent name change. It is perhaps safe to assume that she isn't entirely enamoured with her husband's new moniker. "I told him that if he doesn't go back to being James, I'm changing mine to Beyonce," she quips.

Basford's career as an illustrator didn't fall into her lap. She has grafted hard and there was a time when, by her own admission, she was skint, in debt and had to resort to borrowing Pot Noodles off her mates. Week after week, Basford would make the monotonous round trip from Aberdeen to Edinburgh, Glasgow and London by Megabus seeking work.

While that's all behind her now, Basford hasn't forgotten how far she's come. "Definitely not – it's still very raw," she asserts. "You have to go through that process, though. I get a lot of emails from graduates and students asking – what is the quickest shortcut to getting a really good career?

"You have to work hard, put up with a lot of rejection, be focused and willing to sacrifice a lot. All those years it was really difficult and a bit grim, it does make you tougher, more resilient and focused. I have worked hard to get to this point, so I wouldn't dare squander that opportunity."

Glimpses of Basford's future career could be detected from an early age. While most children go through a phase of scribbling on the walls with a felt tip pen, she took it to a whole different level.

"My dad was painting the underside of our car with some sort of black sealant paint when I was a toddler," she says, fighting a giggle. "And he stupidly left the paint pot in our hallway. I can still recall the strong, bizarre smell of the paint. I got hold of the brush and then painted a big bit of our white hallway black. I remember looking at it and thinking it looked quite good."

Her parents took it all in their stride. "My mum and dad didn't go mental in the slightest. They weren't angry although I think my dad probably got it in the ear later for leaving the paint out. That was my first big monochromatic artwork and installation piece."

There were other signs. "I have always loved to draw," she recalls. "I can't remember wanting to do anything other than be creative. Well, apart from a very brief stint when I wanted to be an astronaut.

"My mum tells a story about a picture I drew of myself in playgroup. It had fingernails, eyelashes and a belly button. Apparently for a three-year-old that's not very normal. I have always delighted in detail and wanted to capture everything I could see in pen or pencil or crayon.

"All the way through school it was art I wanted to do and I was very focused on getting into art school and pursuing that creative career."

She attended Duncan of Jordanstone in Dundee and even then went against the grain. Her distinctive style of black and white drawing, says Basford, evolved out of necessity as much as choice.

"I was super-skint like most students and couldn't afford a laptop, digital camera or even to use the fancy new digital printer in the department, so I very much went back to basics and was using pens to do all my artwork, drew everything by hand and then screen-printed it using ink."

What started out as simply a way to make art that was financially viable, soon set her apart from her peers. "Everyone else was doing computer-generated artwork and digital photography, so my work started to really stand out for being different. I like the tactile nature of working with real materials and creating off the screen with lots of smudgy fingerprints on everything.

"I now champion the pen and pencil over the pixel and all those imperfections that make inky, analogue artwork special are things that I really cherish. I don't like precise circles, straight lines or even vectors. I find it cold, clinical and lacking a soul whereas when you see something that has been created by hand it has a sense of charm and warmth to it."

A stint working in London proved a shock to the system for someone from such a rural upbringing. "After graduating I had a lot of interest in my work which was very flattering, but all of the studios were based in London. I was Megabusing it down and staying in cheap digs because that's all you can afford on intern wages.

"I found the city very claustrophobic. Not enough green, too many people, not enough space. For someone whose work was so heavily inspired by nature – the reason people wanted me in their studios was because they liked the way I drew florals or foliage or animals – I couldn't replicate that work in a city environment.

"It was the time of the 7/7 bombings – a scary time to be in London. Being chucked into the middle of that was a culture shock for me and not something I could have done long-term."

These days Basford has no shortage of ideas often inspired by her daily walks with Simcoe through the Aberdeenshire countryside. "Being out in nature and the fresh air is a great way to relax and get away from all your digital devices," she says. "To go for a walk in the woods or take the dog down to the beach is very inspiring. You see little nuggets for ideas."

Although, in truth, the muse can strike almost anywhere. "It might a leaf that you see in the Tesco car park or the most beautiful tree that you see in Thailand. I store away all these little snapshots and then they filter their way back into my work."

She is already onto the next colouring book – number six – with countless plans in the pipeline. "I have one of those brains that is always thinking about the 10th project away and then you need to rein it in and focus on the current one. Too many ideas, only one hand – not enough time."

When it comes to the colouring-in craze, her philosophy is the more, the merrier. "I like seeing the category blossom," she says. "If it wasn't for that whole table of books in WH Smith or an entire category on Amazon, I wouldn't be in this position. There is more than enough room for everyone."

She loves the idea of people opening up her colouring book as a gift this Christmas, but also hopes it could be integral part of festive fun in the run-up to December 25. Each of the pages in Johanna's Christmas has a perforated edge, which means they can be detached once completed allowing them to be presented as a hand-made gift.

Although Basford acknowledges the book could equally serve as a much-needed de-stress for the frazzled masses. "Having cooked Christmas dinner once many years ago, it was the most stressful meal I've ever done," she says. "I like the idea that, while the turkey is roasting and the tatties are boiling, people can find a quiet corner to do a bit of colouring in with a little glass of sherry."

Johanna's Christmas by Johanna Basford is published by Virgin Books, published £12.99