Three weeks after she found her husband, Tony, dead on the floor in the bathroom, Jan Robinson went out for lunch.

She didn't really want to go - she had loved her husband dearly and was still in a state of shock - but she pushed herself and, there, at the table, she sat down next to a woman who asked her what she had been up to. Robinson blurted, "I've just become a widow."

"Gosh, you're a brave woman coming out," responded the woman. "I'm a widow too."

That was when it occurred to Robinson, a seasoned collector of tips on all aspects of life, to ask this woman for a few. To which she replied that Robinson was already doing the most important thing. She was getting out.

Robinson, a reiki therapist, who had been married for 46 years, then began to gather advice from any widows she met, building her collection till she had amassed so many she wanted to type them up. When she did so, a friend who helped her with the typing said, "Do you know what, I think you may have a book, here? A little 'till tickler'?" So, she decided to publish it herself - and sold 3000 copies. Among those who came across it was a woman who had lost her husband and who happened to be the mother of a director of publishing for Bloomsbury. This widow gave it to her daughter saying, "Why haven't you got this book?" And that is how Bloomsbury ended up buying Tips For Widows: a neat, comforting pocket book on a subject most of us still want to tiptoe around.

"It's only tips," Robinson says. "It's just to reassure some women that they are not alone, they are unique but not alone. There are many women who feel the same things." Joanna Lumley has described the book as a "quiet, wise friend". It's that gentle someone who sits you down and shows you how to reply to the messages that flood in following a death, who warns against perils and advises on questions like whether to drink away your sorrows. Don't move out of your home in the first year, and take your time getting involved with another relationship are among its key recommendations. The Kensington magazine called it the "book that will do for widowhood what Mrs Beeton did for cooking."

"There's nothing like this out there," says Robinson. "There have been books about people's personal grief and very beautiful ones. You get a little bit of information when you go to the funeral director or the registrar, but generally speaking it's not been something that people have talked about."

For most stages in life, she points out, there is advice aplenty. We have a market saturated with books telling us how to care for a baby, raise a child, have a good marriage, survive a divorce, but there's a dearth of practical information on navigating the loss of a life partner. "Yet," she says, "widowhood is like a brand new life. Just like you weren't a mother and then one day you were a mother, the same with being a widow. Birth is well and truly talked about in every single capacity, but not widowhood."

Many exquisite and moving books exploring personal grief already exist: CS Lewis's A Grief Observed, Joan Didion's The Year Of Magical Thinking, last year's hit, Helen Macdonald's H is for Hawk. But a contemplative tome about loss isn't always what's needed, when the fog of grief is too thick to concentrate on more than a few sentences at a time. There are, of course, aphorisms, and poetry, for comfort. But Tips From Widows is not just about this, it is a practical guide - and all the more moving for its breathtaking pragmatism. One of its virtues is it's small: the kind of book, as Robinson says, that slips easily inside a handbag. It doesn't overload, doesn't dazzle with dense pages of words.

But also it isn't too directive. Robinson says, "The last thing you want to do is find out how you should feel. Widowhood is a unique thing for every woman. I didn't want to read about another woman's grief because it wouldn't be the same as me."

What it brings home is the vulnerability of women, and also men, in the months after they have lost a partner. Surprisingly Robinson's strongest piece of advice is not so much for widows as those who anticipate widowhood: "It is essential to have a joint account with your husband. The moment your husband dies, any bank account in his sole name will immediately be frozen, even if you are the sole beneficiary of his will." She also advises not changing accountant in the first year of widowhood, as it might suggest to the Inland Revenue that you're trying to avoid paying the full tax you owe.

Nor does she shirk from blunt truths. One piece of advice is to try not to feel hurt when you are left out of some people's lives. "Fitting in a single woman socially might not be easy for them, and you have to realise you have now joined the band of single women." Another is to take a friend or relative when registering the death of your husband, "since with your emotions awry, you will probably not be able to concentrate."

We are, as a culture, opening up about widowhood. The widow's life is explored elsewhere: in online groups where women can find comfort and support, blogs like Nicola Campbell's Widows Don't Wear Black which documents her experience of becoming a widow, with two small children, at the age of 36. Tips From Widows isn't intended for younger widows - and they might take more solace from Campbell, who navigates her grief in a social media age, while dealing with bringing up two small children and feeling isolated amongst her peers.

Robinson recalls the day she returned from a walking trip to find her husband, lying dead from a heart attack, and she found her own life changed. "Sometimes nature is very kind. It stops you truly, truly feeling the shock of it all. It sort of puts you in a little place of denial, as if your body can't cope with the instant shock. And I found myself being deeply practical immediately." In the weeks after his death it began to sink in. "I just walked and walked and walked and muttered and muttered and cried and cried," she says.

Four years on, she still talks to her husband. When she's anxious about something, like using the computer or doing a tax claim, she asks him to help her on it.

And she can be suddenly moved to tears: for instance when she sees an elderly couple walking along in the street, holding hands. "When I was in a department store once," she says, "a woman next to me said to her husband, 'Love could you please check the back of my hair, I think my bald patch is showing.' And he took out a comb and combed her hair over it and put it back in his jacket pocket. That brought tears to my eyes - the sheer kindness, the little act of love."

Tips From Widows deserves a wider readership than widows. Many of those I wanted to give it to are not recently widowed: my mother and father, friends who have lost parents, divorcees. Almost anyone in fact could benefit from reading this book, since almost all of us are at risk, at some point, of losing a loved one.

Robinson has also considered writing Tips For Widowers. After all, she says, widowhood it's not the same for men as for women. She notes, for instance, that widowers, unlike widows, gain social popularity once they are made single by their loss. One widower asked her, if she was exhausted from being asked out every night. She answered, "Sweetheart, have you not heard of the phrase, everyone loves a spare man?" Indeed, she already has in mind the first and most important piece of advice for this new book. "Don't get married in the first year. You're vulnerable. Take your time. Otherwise you take your suitcase of grief with you."

Tips From Widows by Jan Robinson, Bloomsbury, £8.99