That's the part of honing that I found the most difficult to judge - when are you done with a grid?
There are various ways to judge the bevel setting stage.
1) Most common and reliable way - The burr method: Hone on one side counting the laps, until you feel a burr is formed all along the opposite edge. Then repeat the same amount of laps on the other side and test for a burr all along the edge. This is probably too harsh for something you care about, but ideal for GD's.
2) Kill the edge by lightly dragging the edge in a cutting motion across the stone corner, until you can't cleanly slice paper. Hone both sides equally until you can easily slice paper.
3) Most difficult to judge - the water under-cut method: Hone both sides equally, edge leading until the whole edge clearly undercuts the water, acting like a squeegee.
4) As mentioned above the thumb nail test. Never tried it so I can't speak of it.
Once the bevel is set, I move to 3k, 8k and finally 12k.
At these grids you are more polishing than removing metal, so more is better as long as your pressure is light. I like 50 laps on each side, then 20 laps each side, then 10 each side. This is to remove any burrs and centre the edge. I finish with at least 10 X-strokes, flipping every lap. On the X-strokes I carefully monitor the under-cut of the water on every grid.
I have to add that I have never achieved an edge than I am happy with on a stone and I move on to the three balsa strops before attempting to shave.