I have told you about the three-finger test of edge sharpness, developed by Murray Carter. Another way for testing the sharpness of an edge is with a Tomato, or some other fruit with a skin of some sort. Very simple process.
Very carefully, and with extremely little pressure, the edge of the knife is drawn across the peel of the tomato. If the edge punctures through the peel as the knife is drawn across, it has a sufficient edge, and the rest of the sharpening process can go on. If the edge just slides across the tomato, but does not cut, it must be taken back to the stone, and the primary edge worked on a little longer.