This is a far common question.
We've seen the best pros on the planet doing that, after commiting some chips but saving a bunch.
How do we avoid sets?
I've seen Eric Seidel getting rid of his aces on FTP Million Dollar, Chan doing the same on PAD, the classic Negranu Pocket 6's or Pocket 4's on the WSOP.
I mean, for me this is the most profitable hand (when i hit a set), but the hand i lose the most also.
How do you guys spot sets?