what i did with my 2 yearling females was as follows.( they were 17 inches long at the time.)
i let them get settled in, and start feeding regularly.
once they seemed comfortable, i woulld take them out and hold them on my chest while i watched tv lieing on my couch. i would use my hands to make a hide for them, and give them just enough room for them to poke their heads out. eventually they would get curious and start to look around. then they would venture out fo their make shift hide. it took alot of time, but i gained their trust eventually. in doing this they were not traumatizd early on, so they didnt see me as a threat. they got used to my scent, and were in a nice dark and warm hideing place at the same time. now they have no problem being handled from time to time, and in fact love to come out and explore.
this same method has worked with my leopard geckos and corn snakes as well. it is all about them being comfortable and comeing out when they want to, not when you want to see them.