Airfoils designed for reverse flow
You would copy the cross-setional shape of the frisbee plastic disc toy, which generates lift as it spins and travels through the air by using a shape which looks like the leading edge of a wing no matter which way it is pointing. a wing with two "leading edges" like this is not as efficient as a wing with a tapered trailing edge, but it works well enough to fly significant distances and provide fun for its users.