It's often TPWK, or a flush draw. If they min-3bet the turn is't a set or maybe a stupid 2 pair.

Flop raise is good because you're basically ignoring his bet and cbetting. On the turn I'd just call. If he's on flush draw you're ahead and can check down, if he has a T you're getting odds to hit your overcards.

This also lets you get to showdown so you can see what kind of hands your villains are playing and start building more accurate ranges. At the micros, if I can put someone most likely on TPWK I find trying to bluff them out of the pot to be -eV.