Flopping sets OOP against PFR

[Beck]

This is something that just isn't working out for me,like it should.

It seems the general consensus here is, that if you flop a set OOP against a PFR you should bet out, hoping to get raised, so that you can 3-bet it.
However, only very very seldom do the PFR actually call (or 4-bet) my 3bet. Otherwise they just fold every single time.

So I'm pretty sure i'm dong something wrong.

How much should I raise when 3-betting?
Example NL50, I'm in BB with 55, button raises to $2, I call, flop comes 25J, pot is $4. If I bet $3, he raises to $8, what should I reraise to? $18? $25? all in?

When should I go or a CR instead?

I know it depends on things like my image, opponents aggression, board texture etc.
I'm just looking for some general guidelines.