Here is a video that shows how to select the best feathers or parts of the feathers so they stay on the shafts the best. Also a tip on how to make sure they dont come off.
http://www.youtube.com/watch?v=QxynRhtuzhI&feature=youtu.be

Need to also make sure you have selected the thickest part of the oil line in a feather,it is the thickest part of the actual feather, not the quill.That makes your arrow quieter in flight because it is stiffer,not bending over during the arrows rotation.Also I like a pointed front of the feather so it has a smoother transition between feather and shaft as it passes over the shelf,a dab of glue holds it down.