The straps are long enough on my seat that I just tied knots onto the cushion. When I take it off to wash the bike, I just take the seat off and slide the cushion off.
The knots keep the Airhawk secure, unlike the flimsy little buckles. I ride dual-sport, so I stand up some and need to know that my expensive bum-pad won't fall off, thus the knots! YMMV.
"With the disappearance of God, the ego becomes the sole divinity.” -D. Sölle