Every time someone tells me their meat is gamey I can almost always dice it down to bad field processing. Either they didn't get the meat cooled quick enough, or (especially during rut) touched scent glands/patches on the inner hocks and then handled their meat. I now have 3 rules of thumb that have yielded nothing but fantastic results on many mule deer and also a few bulls. Obviously first and foremost try to make a lethal and ethical first shot, then -
1. Gutless method, skin immediately and get the meat cooling. It spoils from the bone out so if I'm in hot weather with no shade or creek bottoms, it gets boned out and hung in game bags in makeshift shade.
2. Don't touch the freakin scent glands.
3. Don't cut it up for 72hrs minimum. Anymore I hang it in a fridge for a week so it's guaranteed to be relaxed from rigor, I cut a bull up too fast once and the taste was fine but steaks were tough. Learned the hard way.