In order to grind your own Ink, you need only three things: an Ink Stick, water, and an Ink Slab.
Holding the Ink Stick firmly near the end you want to grind from, start grinding the stick in small circles against the Grinding Surface. It is important not to press too hard into the Grinding Surface. Let the Grinding Surface do the work! Pressing too hard may cause pieces of the stick to break off into the Ink mixture. Also, ensure that the Stick is held vertically and that the surfaces of both the Stick and Stone are as flush possible. As you grind, you will notice the Ink thickening. This is the desired result.