I've been having a lot of trouble figuring out what I want to bet on the river when I have something like a lock hand recently. Obviously some of this depends on what the board looks like, but here's an example:

Full Tilt Poker
No Limit Holdem Ring game
Blinds: $0.10/$0.25
4 players


Stack sizes:
Hero: $25.60
Button: $23.75
SB: $10.50
BB: $46.10

Pre-flop: (4 players) Hero is UTG with
Hero raises to $1, Button calls, SB folds, BB calls.

Flop: ($3.1, 3 players)
BB checks, Hero bets $1.5, Button folds, BB calls.

Turn: ($6.1, 2 players)
BB checks, Hero bets $2.5, BB calls.

River: ($11.1, 2 players)
BB checks, Hero bets $11.1, BB folds.
Uncalled bets: $11.1 returned to Hero.

Results:
Final pot: $11.1

I actually don't think I played this hand that great at all, let alone the river, but on to my point. When he check calls the flop my first impression is that he's drawing, so now I make my flush on the turn, he check calls again, plenty of people would do this if they just made the flush. So now the river comes....overall, the flush got there, a bunch of high cards got there, something like 67 would have missed, but I don't think that's a very likely holding. So now the question is, when he ckecks into me again, what do i bet? Obviously if he has nothing, he's not calling anything...but I wanted to maximize my value if he had something like a set he was trying to slowplay and wouldnt be able to let go of, or had made the flush or straight etc. But I think it's much more likely the guy has something like a weak K, so how much can he call on that river? I'm thinking betting like 1/3 of the pot, a K could call and if he had a flush he would most likely CR me anyway, so the only thing I really lose value from is a set. So what do you bet on this river?

I bet 1.50 preflop. Flop I bet 2.50-$3. Turn I bet $6. River I push. This guy seems to be calling down though because he has a draw, maybe a straight draw on the flop. Very strange, but I don't think he had anything on the river...just your normal CS. I just think you need to increase the size of your bets on every street. The bigger the pot is, the harder it makes it for villian to get away.

I agree, I definately think my biggest weakness is that I start off sessions great and I bet normal amounts when I have good hands and then like 2 hours go by and people have instafolded to a bunch of my sets etc. and I get a flop like this and im like OMG LOLZ I CAN'T LOSE I don't want him to fold so then I start doing stupid crap like betting way less than i should.

Yeah, don't worry, they get pissed some when you bet the right amounts too...I swear it. Look at it this way...your opponents make bets like you did this hand and whenever I am doing something my normal opponent does, I fee dirty, like I'm betraying people who play well everywhere.

Don't let this happen to you.

3 on the flop, 6 on the turn, push the river.