For the past few years I've trained my Pokémon evenly throughout the game. It really challenges the player, especially if you choose your team without thinking strategically, and just basing your party pretty much on who you like the most physically. But it's a lot more fun! :o)
Regrettably when I was just an adolescent, I sprinted through the games as fast as I could and didn't even read the dialogue..
The biggest thing I can remember was, on my character named "AAAAAA," raising my Typhlosion in Gold, nicknamed "AAAAAA," which sat at level 100 (entirely legitimate), along with five HM slaves. LOL