Misapplying A Concept

So I still haven't read any books on NL, this forum has been where I've learned everything so far. HOH1 is en route as we speak, but until then...

I think I may not be too clear on when to check on the turn when holding TPGK, or TPTK, either in position or out.

Obviously out of position we don't want to build a huge pot, but is this less of a factor against a very predictable player, or a total donk? I'm much more likely to check turn oop after potting the flop if our opponent is a LAG, or a good player. But if opponent can call anything I like betting, or if I know for sure a raise means I'm beat I don't mind betting, or check/folding.

What about in position? I can see checking turn against good players after they called a pot sized flop bet because there isn't much we're beating, or they're calling with 3 outs, or checking behind LAGs because we don't want to be blown off our hand. Against bad players we just bet bet bet, right?

Are any of the reasons I mentioned significant? Am I missing something more important?

I know it'd be better posting individual hands, was just hoping someone could explain the reasons why we check sometimes and bet others.

If I need to be more clear, please let me know and I'll try and focus the question.