Freehand grinding

As the name suggests, the aim here is to achieve the cutting edge angle simply by holding the hand correctly. Here, it is best to feel the two tipping points (each marked with red) with 2 fingers and press them down constantly while grinding. This angle must then not be changed during the movement. This trains dexterity and coordination! Nevertheless, it will be hard to avoid that the bevel will look like this after some time. The idea with the tipping points assumes, of course, that the cutting edge angle is essentially correct. And that means that the process is mainly suitable for simple resharpening.

Fig: Tipping points with a flat bevel (reasonably tangible)

See also The flat bevel

Fig: Tipping points with a hollow bevel (somewhat more tangible)

See also grinding: the hollow bevel

Sometimes an angle stop is helpful. The only tool that an sportive professional will accept. Of course, only to tune the muscle memory. It is then taken away during grinding:

Fig: Angle stop with 25 degrees, from 3D printer