I think the answer is lots of playing Mario games and games similar to them :-)
Yes, this is an option. It can strengthen your skills in many different ways. However, seeing how most MF games that have been released lately aren't very difficult (no offense to anybody), you will find yourself in a plateau. Good difficult games include: MV3410 World S Crist1919 Worlds -5, -7, -10 MF All-Stars Syzx. World 12 MrPrzemistrz MF Roman Worlds (especially World IX, X, XII) Note that this is not an exhaustive list and there are plenty of other good difficult games out there.
It's all just pure skill. There is no tutorial or explanation to it. But, there are lots of tricks most people use... Which I myself don't know of
Skill is something you gain from playing many MF games. The tricks and precision moves that you may see many good MF players use need to be learned, not experienced. That's a bit different.
Some people do ask me how I am able to play through a difficult world without death on just the first try. And my answer is this: You need 4 main virtues: mobility, agility, reflexivity, and technicality. If you can master all four of these, you will be a very good MF player.
It's a funny but interesting question at the same time. Everything depends on skill. If you do not have a good skill, you can not cross different levels of difficulty. Neither can I say that I am a very successful player, but I play quite well given the fact that I am creating pretty hard levels and games. First of all, if you want to become a pro, all you have to do is stay based on the game you want to be good at. For example, I play MF in 2009, I heard from a friend of mine (he died from brain cancer in 2016) . He played very much on this game and was pro, because his computer was very weak, she could only play games with poor graphics. Just Mario Forever was playing all day and he liked it a lot. He was so professional that even Akos Wittmann did. The secret is just a word: skill.
master171. aka Jay Lenner, gameplayer and creator.
Practice so you can gain better skills. Worlds on mariogeek1234's list are surely great to practice. If you have skill to play them, you will see your progress quicker. And if Roman Worlds is too difficult for you, try some easier game first If you are a new to MF, original Mario Forever / Mario Forever Remake may suit you best, as it is classic and one of the easiest MF production. If you cannot pass some hard worlds, try this first. Then you could try some of the harder games. Anyway, practice makes perfect. Hope you can be a Mario Forever pro soon
My main current working-on projects: * Mario Forever: An Unprecedented Exploration (Main project, 0.4 released) * ????? ??????? ????? ?????? * Legend World Remake (Supporting project) Too many projects :v