A big thanks to Mike Lovelady for carrying all of the equipment for the weekend in his truck. Minimum preparedness consists of carrying a big plastic garbage bag, preferably orange or yellow. If you're lost and the temperature drops, just punch and stretch a hole for your face on one side of the bag near a bottom corner, then pull it over your head and body. The bright color helps searchers find you. You should also carry matches or a lighter in a waterproof container.
Water is also a good idea.
To avoid getting lost, turn periodically to see where you have been as well as where you are going. Familiarize yourself with your path and remember landmarks. If you're really serious about this, you might want to mark your path with bright flagging tape and take it down as you retrace your steps. If you own a compass, use it. If you do become lost, it may be best to stay in one spot.