bagem brings up more to comment on. Helical. Yes helical is a great aid and a good way to fletch an arrow to optimize spin compared to straight. I'd recommend buying a jig like the Bitz with a straight clamp. This allows you to adjust the jig to fletch with an offset. (Offset fletch lays across the shaft at an angle/Helical wraps around the shaft) With a straight clamp and offsetting the jig, you can control rest clearance if shooting through a shoot through rest, if your using a drop away, that isn't an issue.

As Rick James pointed out in another thread and I concurred, Offset will do the exact same job as a helical, but you have more control over the fletching variations that are sometimes needed.