If you want to learn to control Buck Fever, all you need to do is take the competition out of the hunt. You need to decide before the season starts that you are not going to kill a buck unless it is a contender for a new world record. Then when you are actually hunting, you can pass up all of the little and medium sized bucks you see. You will notice that after you let a few get away, you aren't nearly as excited by the next one you see. If you see a really BIG one, and you've already decided to pass up everything smaller than the world record, you will be trying to come up with reasons to shoot the big one, instead of getting too excited about actually getting the shot. It will make you slow down a little and think about what you are doing.
"Wow, there's a big one. I can't pass on that one, I'm going to shoot it. Wait, I wasn't going to shoot anything this year. He's not that big anyway, right?. He is the biggest buck I've seen in years. I don't know, maybe I will take him. He's just standing there waiting to die anyway. If he stands there long enough for me to get a good dead rest, maybe I'll shoot him." Then you get him in your scope, safety off, finger touching the trigger. You look his antlers over carefully through the scope and decide "dang, he has short forks", or "He's a little weak on mass", or "If that one point wasn't missing". If I keep hunting, I'm sure I can find a little better one before the end of the season."
If you take away the anticipation of getting that one and only shot, you will notice that you are more relaxed and can enjoy the hunt alot more. The pressures of succeeding will fade away. This works equally well if you take a youngster out hunting. Show the kid a few animals before expecting or allowing them to shoot. In fact, you should talk the kid out of shooting the first few bucks they see. They only get one "first", so tell them to make it a good one. If they don't get a buck after hunting the whole season, offer to buy them a steak dinner and promise to take them again next year. Then they can go into their second season with the idea that they will see a few bucks, and they should try to hold out for one of the bigger ones.