Originally Posted by Tom P
They will put you in a jumpsuit anyway, so just wear what's comfortable.
Comfortable shorts, T-shirt, (No Collar!) A collar will "whip" your neck bad in freefall. Your fav tennis shoes. (tie the laces good).
Nothing in your pockets. As you sit in the aircraft, anything in your pocket will "bind" and you won't be comfortable.
Harness. Snug yet comfortable. Do not tighten
the leg straps as you sit in the plane. Do it on the ground. If you do this, the harness will be TOO TIGHT
for you on opening of the canopy. Don't put anything between you and the leg straps, you want to keep.