Some snakes can never be handled properly as they cannot be tamed like other animals can. I love snakes but they are not...smart
I had one little bugger that bit me as soon as he hatched and he never stopped trying to kill me in the 18yrs I lived with him
IMO all reptiles should be handled as little as possible; not only because of stress (some people do not even recognize stress in reptiles) but also for health reasons. Both for the snake and the owner. I always wash my hand before and after handling and try to keep contact brief.
My current corn snakes are hand fed (with hilarious consequences such as trying to eat my fingers because if it smells like mice it probably is a mouse). I hope they will start to notice that handling equals food and fun instead of terror but it's a very long shot.
I don't do this to cuddle with my snakes, reptiles are not cuddle-buddies no matter how much people say they are, but in case I need to handle them for health inspection/cleaning/etc.
The female corn snake I have now, Ishtar, is very relaxed and doesn't seem to care what goes on around her but Voldemort, the male, is a bit more stressed and is treated equally; as soon as he is done feeding it's back in the terrarium with him.