I have question about pot odds.

My friend says I should bet less or just call when on a draw, yet I hear others say you should pump up the pot while holding a flush& straight draw to make the implied odds higher. My way of thinking is not to bet if you dont have a made hand, then if made pound it.

Also, I get confused about betting with say TPTK. I've heard some say to price out the pot and bet high to make those drawing fold. Yet I've heard some say not to make the pot too big and increase the pot odds that would allow the drawers the right odds to keep drawing.
I usually try to bet the drawers off their hands.

I am missing something here?