Receiving oral sex is amazing. Obviously but a big part of the pleasure I get from it is that she likes doing it. When she is into it you can tell, and it kinda turns into me cumming as a reward for her in a way. It shows her that I was enjoying what she was doing and that I appreciated her efforts. Its hard to explain but hopefully that makes sense. To take it a step further, it does have to have different levels to it. It can't just be bobbing up and down for 15 minuts. Apply different amounts of pressure, different rates of speed. Adding noises from time to time, and letting things get a little messy and wet to show how into it you really are. So the main things for me would be - an attitude that you are enjoying yourself while giving the blowjob, and variety during it as well. Keep me guessing what you're going to do with it next!