One more thing: once your snake learns to recognize you by your touch & scent, don't rush them when you pick them up...give them time to "remember they know you"-that way you aren't stressing them so much.
I had to do that with that boa...once in a while, her thoughts were "elsewhere" & she'd let out a huge hiss to say "I want to be left alone"; I slowly stroked her coils (not "in her face") until she got quiet, just a few minutes at most, then I could pick her up as if nothing ever happened. They are snakes first, who knows what their thoughts are? -but empathy is the cure.