Try putting your opponents ona range of hands and narrow that range once the hand progresses.
Example: You hold AK and raise in MP, the button calls. Flop comes J36rainbow. You bet 2/3 pot to have him fold, BB flat calls. What can villain have that he can calla bet on this flop after calling our raise ? Medium to smallish PP (88, 99, 1010), a small to big J, Ax, etc. He might just peel one off for a gutshot or to keep you honest, figuring you haven't hit this dry flop (you have raised in MP and only AJ and JJ hit this flop hard enough).
Turn brings a K. You bet again, this time 1/2 the pot: he flat calls. Now, med PP become very unlikely, has does a small J or Ax. You have raised preflop, A7 or even A3 or A6 will usually fold here. AJ, KQ will possibly raise, as will AA (figuring you have it) to take it down: AA is unlikely though since a reraise preflop is almost mandatory. Ak is also possible, but I see AK also raising here. A set slowplaying might just call (KKK, JJJ 333, 666)
This is usually the tought progress you should have. In the example, on the flop, villain can have a lot of stuff, but on the turn, the range is much narrower since gutshots, semi-bluffs and the like become very, very unlikely: sets and big hands call this turn, fair hands usually raise/fold.
Knowing this, we either shove or check/fold check/call river if we are unimproved.