Thanks for the fast responses guys...this has always been one of those areas that I've examined as a possible "leak" in my game because really, giving money away and not asking for enough of other people's money when you have the opportunity to get it all winds up in the same consequence to the bottom line. It just got re-kindled last night by the following hand...
0.25/0.50 NLHE @ Paradise
UTG +1 I get dealt

and raise from 0.50 to $2. Callers in MP and LP plus the small blind. $8.50 in the pot.
Flop
SB checks, I bet $9, MP calls, LP and SB fold. $26.50 in pot
Turn
Flush doesn't really bother me since he called my pot-sized bet earlier and hasn't struck me as a chaser. Plus I've got re-draws with my ace even if he has it. I bet $13, he calls. $52.50 in the pot.
River
So here I am with my dilemma -- nut flush, how hard do I push? I've got about $45 in front of me still and he's got $40 or so left. Its a scary board and I'm fairly certain one of his cards is not a heart. I throw in $10 thinking he almost assuredly has to call that with any sort of hand given the pot size and hoping me backing off a few bucks might induce a bluff/steal attempt (which I'll be more than happy to call.)
He calls, flips over

and says "good thing you didn't go all-in, I'd have called."
Nice pot, but $30 lost by not asking for it.