everyone's body is different, and therefore different things may work well for you and not others
there are things that are consistent with both that you should emulate:
1) wrist stays locked until the follow through
2) L shape in elbow
3) "ten toes to the hole"
4) finishing with elbow above eye level
5) ball never touches their palms
from there just shoot the ball and make sure you are comfortable doing it
in terms of stamina find a friend and do this drill: http://www.youtube.com/watch?v=npOv7j8usTI
makes are 1 misses are minus 2 and you are trying to get to +5. Then try to get to +10. It's alot harder than it looks
then, when that's too easy for you do this drill: http://www.youtube.com/watch?v=lyWFyx9jhhE
these are really great drills that I have used since HS, I'm very confident with my shooting ability now. I'm 6'2 but I play with a lot of bigger guys so I have the same problems as you getting my shot off.