Roy Hodgson's young squad failed to make it out of the group stages in Brazil following two defeats and a goalless draw - the national team's worst performance in half a century.
However, Martinez feels the experience will have proven key to the development of players like Toffees 20-year-old midfielder Ross Barkley, Liverpool's £25million playmaker Adam Lallana and new Manchester United defender Luke Shaw, who are all expected to have integral roles as England look to the future at Russia 2018.
Speaking to www.fifa.com, the Spaniard said: "I was very impressed with the manner that England approached the competition.
"Looking back at other tournaments, it was the case of trying to progress and go through. This time around, it has been a clear approach of: let's try to be ourselves, let's try to find solutions and learn from the experience for the future; if we progress in this tournament, great, if not we'll get the benefits.
"There is a real legacy growing in this new England set-up.
"I love the eye-to-eye mentality and having a really brave outlook about their performances.
"The defeat against Uruguay was marginal. The game against Italy was very small margins as well, not to get the victory.
"Overall, it's a positive approach, and I think there is an understanding from the English public that there needs to be a bit of patience and a structured path to be successful; not just to be good in big tournaments, but to try to win a big tournament.
"To get there following the methods of Belgium or even Spain takes time.
"There has been a step towards achieving that with how England allow youngsters to have a major say and develop a clear way of playing that is going to be very beneficial for the future."