A lot of people feed their pet snake in a place other than the snake's normal enclosure. This prevents the snake from associating hands and opening cages with food. Some people have a specific feeding box or tupperware, but for smaller constrictors a really common method involves sticking the snake in a plain paper grocery bag with the food.
Since neither of my snakes is huge, this would be an ideal feeding method. Unfortunately, I cannot seem to keep a paper bag in the house for more than 30 seconds without it becoming occupied.
I'm pretty good at keeping the cats out of my gift wrap though. I hoard gift bags so that I can reuse them, and I have one that is exactly the right size and shape. It's nice a sturdy, and the top can be secured with a large chip clip. It's the most cheerful place I've ever tossed a warmed-over dead mouse.