It depends, for me, on how I'm feeling that day, and on how many feathers I have.  I love the Indian eastern woodlands spiral fletching, so I try to do that on both arrows and darts - only requires two feathers, it's authentically primitive, looks really brilliant, and is accurate, because it causes the shaft to spin like a rifled bullet.  Or sometimes I'll use three feathers.  I don't use glue to hold the feathers to the shaft, but I do use some resin to secure the bindings.  If you want to find out more about the two feather spiral fletch, I'd advise the purchase of "The Encyclopedia of Native American Bows, Arrows and Quivers, vol 1", by Jim Hamm and Steve Allely.  I'd buy it anyway, if I were you.  It's great.