Martinez led Everton to a fifth place finish in his first season in charge, amassing the club's best points tally for 27 years.
Having reshaped his squad over the summer, Martinez says he now has the right balance between youth and experience as he prepares for the Premier League opener at Leicester this weekend.
Speaking to Sky Sports News HQ, he said: “The Premier League is tough but for the right reasons. That's why it is the best league in the world – because of the competitive edge.
"Last season 72 points was not good enough for the top four but for a number of years before that it was. Every year the margins get smaller and it's good to see other teams making investments and getting stronger.
“Time after time we see a stronger, more competitive league and that's what makes it the most unique league in world football.
"Our priority was continuity, continuity on all fronts. Obviously we had two very influential players on loan - Romelu Lukaku and Gareth Barry. To have them now as permanent signings needed a lot of effort especially from the chairman and the board.
"We managed to do that, then players, young and experienced, signed new contracts - Seamus Coleman, Ross Barkley, John Stones and Tony Hibbert. We need to be well structured and have a good strategy for the future.
“Handing those players new contracts shows we have ambition, and it is something rare to have Barkley, who knows his best environment and he wanted to stay at Everton and carry on developing here. Sometimes to keep a player is more satisfying than signing one.
“It allows you to have continuity to face of all the demands of the season with a strong backbone and then it's about adding fresh blood, new players who bring something different."
Martinez also confirmed that he is confident of completing a deal for Chelsea winger Christian Atsu before Saturday's game at the King Power stadium.
Atsu has yet to make a senior appearance for Chelsea and spent last season on loan at Vitesse Arnhem.
“We're very close to announcing a new signing – a season-long loan for Christian Atsu. I expect the deal to be done with Chelsea," said the Spaniard.
“The arrival of Muhamed Besic also gives us a different player, adding something very different to the team.”