I hear you. I prefer to have this sort of thing fit in with the game.
For example, in a 4th ed D&D game I knew that at my next level I was going to to be adding a bunch of languages (I think maybe a feat and a familiar?). So I had my chartacter pull out a "Language stone" - completely made up magical item that he used to "Brush up on some languages he'd gotten badly rusty on".
In much the same way, my character will be "Studying magic" for ages before taking a level in wizard if I can do it.

But also, sometimes the party needs X and so the team player thing to do is take a level in X, or you realise a level in Y will make the character more fun to play, and that's fine too