I'm brand new to the position, but not to stopping pucks/balls/etc. I've been reading this board for many hours and hours, and have been spending most of my waking (and some of my sleeping) time thinking about goal tending.
I've come up with a method/way/thought process for keeping my trapper in position:
I hold my glove out in front of my pads with my palm facing the puck with my thumb and index fingers at about 11 and 1 o'clock on a clock face (so far this is pretty standard really). What I use to maintain this positioning almost sub-conciously is a mental technique of visualizing the puck flying into my trapper.
I think of using the force like Luke did when he was trying to retrieve his light-saber when he was hanging upside down in the Wampa cave. I literally try to use telekinesis to get the puck to fly into me. I'm thinking sort of a 'come to me, come to me...' while tracking the play. It sounds funny, but it seems to work. Not to mention that it's fun when the puck gets shot glove side and you snag it.
Craig