The best glider I've seen -- supposedly designed by a NASA engineer, although I have nothing to back that up -- is also one of the simplest.
Fold an edge over itself a couple of times, about a cm or two, to create a weighted edge. Then crease the entire sheet at regular intervals perpendicular to this edge, so it forms a curved surface. That's it!
ooh a flying wing ! i have tried this a number of times myself, and it works great indoors. however at the two extremities, i generally fold into a canard like thingie... works fine.
Fold an edge over itself a couple of times, about a cm or two, to create a weighted edge. Then crease the entire sheet at regular intervals perpendicular to this edge, so it forms a curved surface. That's it!