Tight Agressive Squared.
I read this in a book and tried it out. Under 20dollar buy in, AA KK go all in pre flop, QQ AK bet big but not all in, all pocket pairs limp in if you hit trips go all in, suited connecters limp in, a-x suited limp in. The goal is to double up before 4 players are left. Play only those hands untill there are 4/5 players and then just bet big to steal blinds and add or get back your chip stack. I did this in a 5+50 sit and go and ended up winning 2nd and got 15 dollars. Trust me on this one it really works.