EXPERT BLUFFER WANTED !!!!!

[50OUTSonThaRIVR]

Im an avid fan of freerolls and I was wondering if any of you could help me out. Often during tourneys I go up against high pocket pairs with nothing but the intention to crack them(or make my opponent believe I did). I usually have no problem reading my opponent, but I can never figure the right bet to get him off his hand.

In the last tourney I played, I was calling with 7s and my opponent had Ks. He raises preflop, then comes the flop 9 high. He raises again and I call. Then turn comes an A. He checks.
Our stack are 20K and 16K(me) and the pot around 4K [average stack is around 6K].
Here is where Im stuck.
This time I checked untill the end and there was a free showdown. But I often try to steal those pots and it never seems to work as the players refuse to fold their lovely pairs.
These situations usually end up in heads up and my opponents never believe me when I try to represent a straight, an A, or whatever there is.

Taking into account the fact that I do have a tight and good player image, I am convinced it is only a matter of knowing how much to bet to steal those premium pots and get other players to tilt after they folded premium hands.

Any suggestions are welcomed. :P

[drmcboy]

players in freerolls don't care about your image.

If you can't make them fold, make a better hand and show it to them.

[Sprayed]

Can't bluff people that don't fold.

[mcatdog]

Taking into account the fact that I do have a tight and good player image

Well your first mistake is taking this into account in a freeroll.

[JR9477]

What is the point of tilting freerollers, don't they play bad enough as it is?