This is what I do:
1. I know where the opponet is and take in consideration of where my other opponets are.
2. I take a quick look and then go back in without my gun sticking out.
3. I then burn the image in my mind so when I pop back out with my gun out this time so I know exactly where everybody is and shoot no more than 3-5 shots.
this is what works for me i dont know about every body else.