I'm gonna have a friendly tournament with some guys but I don't have the slightest idea about PvP

Could you share with me some cheap dirty tactics I can use even with my shitty captured pokemons?

Some of them play a lot so I don't expect to win, but I'd like to win at least the other pve-only faggs like me. Or at least win a single match.

So, any tips? I'm open to use any non-legendary pokemon that I can capture and any tactic, doesn't matter how cheap or dirty it is.