Never smoke around aircraft, hangers or pumps. Both aviation fuel and aircraft dope present a great fire risk.
When moving light aircraft, be careful where you push. They are covered with very light fabric or metal and are easy to damage. The pilot will show you where it is safe to apply pressure.
Beware of the prop. It is difficult to see and will make quick mincemeat of anyone who walks into it. Always walk around the back of fixed-wing aircraft and in front of helicopters. Stand where the taxiing pilot can see you; his or her forward visibility is not good. Get into the habit.
Leave the dog and the children at home, the airport is not a nursery. If a play area is made available to children at the DZ, remember that they are still your responsibility.
If your airport has more than one runway, stay off the active one. It will normally be the one running the closest to the direction of the wind. Remember that planes usually takeoff and land into the wind so look for them downwind. Rules change from airport to airport and at some you will not even be allowed to cross the active. Do not walk down any runway and do not fly your canopy over one under 500 feet.
Be nice to all the pilots, they have a lot of clout at the airport and you may need one to fly the jump ship. Be patient with the whuffos (spectators), they are public opinion.