RamenShooter turned me on to a great trick!
I used to fletch my flu-flu's the spiral way, but there's a MUCH easier and effective method:
Use untrimmed feathers (full width) and shorten them to 5" in length. Now, using four of them (I like four fletch for all arrows - no cock feather worries) mounth them on your arrows BACKWARDS, that is, with the "grain" going opposite how they're normally mounted. You'll find your arrows will fly well, slow down quickly, and the fletching will last much longer than the spiral mounted ones will.
Good luck!