A little bit nock high is okay, as it gives you a margin of error for the arrow to clear the shelf. I like it when the bare shaft groups with the fletched arrows at 20 yards, but with the nock on the bare shaft showing a little higher than the nocks on the fletched arrows. If the bare shaft hits way lower than the fletched arrows, or takes a noticeable dive, then move the nock down.
Sometimes you will find that your original symptoms change as you make corrections, for example, when you get your nock where you want it, you may find that your nock left changes to nock right. Usually not. But it can be somewhat of a back and forth process.
It is easier for me to do the first round of bare shaft tuning with my bow in an upright position, since nock high and right may really mean only nock high if the bow is canted to the right. When I get things about right, I fine tune with the bow in my normal canted position. Most of the time, I don't have to change anything at that point.
If you find that you can't eliminate the nock high/low condition within a reasonable range of nock positions, say 3/8 - 3/4", it may mean that the tiller of the bow is off. Most of our traditional bows don't have adjustable tillers, so at that point it is either live with it or back to the bowyer for a tiller adjustment.