I'll add to the pile of dumb crap people do (I'll admit to doing this a few times too but I was too young to care at the time..) Don't get high and ride. Seriously. Its dumb. No one wants to get behind your Rally van going all 25 MPH up county roads on the way to the hill pothead. No one wants to share a lift or mountain with someone all screwed up.
Particularly with spring riding...the hill staff have to be dilligent in closing off trails and marking hazards. Not doing it is just lazy. 99% of places I've been to are good about this. Any staff that isnt shouldnt be getting your money.