Raise hands that will be ahead of their limp-call ranges and can play well post-flop (ie better broadway hands, especially suited, and big pairs). Don’t be afraid to limp behind or overcall in late position if stacks are deep and you have small pair/suited connector sorts of hands. Make bigger than 4x raises preflop if people are still willing to call them. Don’t get me wrong, though, you WANT the four callers. Don’t start thinking you have to “thin the field” when you have AK or AA or whatever. You want to make the largest raise that will still get called by 74s and A5o and whatnot. Yes you’ll win less often in a five-way pot than a heads-up pot, but that’s ok, because you’re also winning larger pots when you do win, and you’ll win more often than anyone else.