To always have a well balanced team, so it would usually consist of the following: A lead, a strong defender, a Powerhouse, a strategic, a healer and one with an overall balance. Sometimes, I forget about this usual routine when it comes to the in-game play, but I like to swap or change my Pokemon in and out to different ones, just in case I'm competitive battling.
I've also found it easier to battle against other opponents, if my Pokemon have most of the type sets, so I'm well prepared for anything.