Keep eyes open, listen, bring a brain to work, do not walk under a tree unless you know exactly what the climber is doing, when you walk under the tree shout "below" loud enough for a climber in ear muffs to hear especially when bent over picking up sticks, never let a rope go near the chipper, keep the site clean, don't let a big pile of **** collect on the floor near the chipper feed tray, keep tools together and out of walkways, treat tools as if you're paying for them, drag as much brush in one go as you comfortably can without damaging property, don't stop working till the job is done or till the man in charge does, don't whinge about mincy bollocks that no one cares about or wants to hear, be polite and don't swear, be the first to do something that needs doing instead of waiting to be told, do not let public into the drop zone without getting permission from climber, assume every member of the public is a suicidal lunatic with no intelligence until they prove you wrong and even then don't trust them.
That'll do for starters