Some people just should not hunt. Was chatting w a guy at the end of a hunting day and he admitted to having taken 6 shots at a White Tail and still hadn't anchored the thing. Its just not that difficult to spend a little time practicing at the range.
I don't get the whole "buck fever" thing. I've killed loads of different animals and the only thing going through my head when the trigger breaks is the technical aspects of the shot ... range, elevation, wind, mover speed, trigger squeeze.
Shooting gophers is excellent practice for field marksmanship. It teaches you to get on the target and get the shot off right quick, before the little bugger moves.
Military sniper matches are also good for the development of marksmanship skills and teach you to ignore everything except making the shot under a time pressure. A 5 second exposure at 800 yds requires a calm head.