Definition of multiway
There is no magic formula for playing multiway pots, but let's just say that the best advice we can give you is to play the pots more conservatively. You can always bluff one or two players after the flop, but when you are say 5 on the flop, your bluffs will be much less successful and you are probably better off not taking them out in the multiway pots (we'll also say family). The average hand that will win the pot on the flop will also be stronger when you are in a multiway pot. While in heads-up play you can win a pot with top pair, in multiway pots this will be more rare.