Pre flop: You need to throw a bet out there that is big enough to isolate yourself against one or two players, but not big enough to kill you if an ace flops. Takes a little skill, but a raise to 3xBB is usually good enough, unless it is early in the blind structure...where you may need to raise it to 5xBB.
Post flop: If an ace doesn't flop, you need to put pressure on your opponent. You can't slow play here and a check-raise is only in order if you know the guy behind you (if there is one) will bet. You can't give away free cards, so bet your hand. Its often said that if an ace doesn't flop, you should push all in. If you want to follow this theory, be prepared for the occasional suck out - knock out.