I place the prey item in the shoebox with the snake, and put a blanket over the rack, and go away for awhile. I am not a hoverer (my husband is! but he does not feed the snakes.. and if he is there while I feed, I make sure that he does not hover.
Haven't tried the bag technique. I think I'll drive up to the liquor store and buy a bottle.. those paper bags they give are the perfect size!