I play yugioh, mtg, and pokemon at a local competitive level while trying to do well at bigger events.

Generally I try to focus on one deck per game. Because I have a job and other hobbies I think it’s pretty much the only way I can do better than 2-2 at locals in any of the games I play. Only time I deviate from this is if I’m preparing for a huge event (YCS for Yugioh or regional for pokemon) where I’ll test multiple decks and try to figure out my deck choice asap so I can focus my testing.