Proper Posture when working with easel.
Good Drawing or Painting skills is a complex and multilayered knowledge.
This knowledge includes some very simple physical features, that can be easely understood when being clarified. In order to make a good learning progress, we have to look at our drawing objectively -- just to see it in a proper way.
In order to see it in a proper way, we have to position the easel in a proper way.