My solution when people are folding to your preflop raises (assuming all are of standard size, within the bounds of what I've mentioned before): raise more. If it happens two or three times, wait 3 hands and then if the pot is limped to you, raise no matter what your cards are. If they all fold, show. Late position helps to ensure they're going to fold, but it's not vital for this to work. You will start getting action after the whole table sees you raising with 72o and then rubbing their face in it when they all fold. Once this starts happening TIGHTEN UP again.