Dude, frankly ANYONE can shoot a bowjob scene. You ain't no stud if yer only shooting BJ's. Sorry.
You gotta monkey-fuck them like no other, like in this clip (near top right of page):
http://www.hotamateurmpegs.com/sophia.html
The key to fucking chics on camera is NOT how big your cock is or how big your load is. It's being able to do EVERYTHING opposite. When you are DYING to burst your load, you can't. When yer fuckin' tired from a two hour shoot and you don't wanna cum anymore, you must. THAT is a stud. In most of my videos I'm pulling 2 cumshots. One from the BJ and one from the fucking. It's all a mind thing. Focus on the girl, don't worry about everyone standing around. Some of my best shoots were studding for the Score Group, where there were many extrenous people standing around. Just concentrate on the girl. It DOES take practice. But it's in the "letting go" , not in some trick seceret you have to think about or learn. DON'T THINK. FEEL. THAT'S the key. And Viagra doesn't hurt! Hahahahaha...