In a Perfect World.
Long before the event, Pilot and Co-pilot and Some Wiser Heads get together to do a Risk Assessment.
1st is that the Grumman Mallard that has sent many fine souls off to first name terms with God. This may or may not be of concern. But if this is a machine that does not tolerate errors gladly then that is a matter to be considered.
2nd is that people die at Airshows in many ways. Is there an opportunity for this to happen?
Consider doing some time to address the stall at low altitude. Both pilot and co-pilot spending time in a cockpit of a sailplane doing endless turns on the edge of a stall, might prove useful.
Have a plan and be wary of the stall at low altitude. Do a few hours in the air learning how this beast behaves at a reasonable height. Learn how to recover and definitely learn how to pick up a stalling wing. Get your co-pilot up to speed on going full throttle with propellers to low pitch. Be ready to get out of trouble.
Learn the ancient and honorable art of sideslipping.
Practice landing somewhere else which is like the area you are to land in if possible.
Ask some questions like: Where are the windsocks to be located?
Is there enough room for a safe circuit ?
Ask yourself, why did all those airshow crashes happen and is this going to be more of the same?
Leave the passengers at home.