Depends on what I am using the arrow for. First of all I am right handed.

For my hunting arrows, I use Blazers. I put them on with a pretty good helical, and I use left helical. It doesn't really matter what direction helical you use unless you have broadheads that have blades that are on a certain offset, or if you are shooting feathers. If using vanes, and a straight or mechanical broadhead it won't matter a bit. I use left because I bought my Jo Jan 6 fletch used and that was the helical clamp set that the previous owner happened to have.

For 3D, I use a VERY tiny bit of offset, however not much. For skinny long distance field/fita arrows I use a hard offset, and the same for spots.