Don't try to be perfect. It's actually not as hard is it looks. Mind your knife as hunting knives are usually sharp as hell, and a deep cut far away from medical can be disastrous. Speaking of sharp knives, have a sharpener with you. When you feel the knife getting dull, take a sec to touch up the blade. A dull knife makes you force cuts. Forcing cuts begs for mistakes. Go slow.
Try not to poke the stomach or the bladder. However it's not the end of the world if you do.
Good luck!
Gary
Also, if archery hunting, be very careful, especially in cold weather and your fingers are cold/semi-numb......locate the broadhead so you don't cut your hand. I've seen a nice buck walk through my yard with an arrow sticking out of his hind quarter.......if that snaps off and a hunter shoots him later, that could be a hidden disaster waiting to happen.