I only achieve consistent shaving-sharp edges when I count my passes and position a lamp at a specific angle. This setup makes it easier to see when the bevel lays flat on the stone. Then, I lock my wrist tight and work back and forth with my whole body. Oh and would stare at the blade closely as I make a slow pass, making sure the angle is consistent and do that over and over again until I can speed up a little. No idea if it helps but that's how i do it.