My method of wrapping is to start from the brake lever body and out to the stem and bar end. That way you don't end up catching/pushing on the edges of the tape when your weight is pushing against it from the drops or the tops.
I've done it that way per what I learned in the 80's. I missed doing the same on my recent build, but I'll definitely do it that way when I replace the tape on my PSV sometime in the near future. Never had the bar tapes develop any gaps or loosening with this method of wrapping.
Chombi