If they are right wing go right helical. If left wing go left helical. Simple enough.
Like any other fletch maked sure that the bases are making good contact from end to end before gluing any.
I have used FletchTite Platinum and Gorilla rubberized super glue. Both work, but the FTP dries cleared and Gorilla is hazy white. FTP takes a little longer to set up, though. I put a bead of glue on the bases then dab the base on a piece of paper to remove the excess and spread the glue across the base. I makes for a perfect, neat fletch job every time without lots of "bleed out".
Take your time. Using FTP you should leave the feather clamped for about five minutes each. This will take about 3 hours for a dozen arrows, but they won't be able to be pulled off. Add a small dab at both ends of the feather after fletching to keep them from getting messed up in deep target penetrations (and the drop on front makes them quieter in flight).