How to write the dots and strokes in hard pen calligraphy? How to control the thickness?

Hard pen calligraphy is divided into dots, strokes and thicknesses.

The key point should be that the pen tip enters the paper quickly, and it should be light at first, and then it will gradually become heavy, so that the points written are from fine to thick.

A stroke is similar to a pause, except that you stop a little at the corner, and then the pen quickly strokes to the right (not too long) and leaves the paper in the process.