Need Some Help

[ATLBrvs326]

I have a vague question that most of you definitley cant answer because it is probably so subconsious to a lot of you. However, my problem is I miss a lot of fouls mainly because I have no idea what to be watching. Told you it was kinda vague. For example when the ball is coming down the court, I am watching the defense for fouls. However, when a player sets to shoot the ball am I supposed to watch the offense and see if someone fouls him? How about underneath when one player is trying to go up with the ball and there are 3 defenders trying to block the shot...do I watch the offense? How about on a fast break and there are 2 players next to each other running fast...what do I watch. Sorry for a tough question but any answer would help. Thanks.