As I have gained experience over the years I realize that art is done well with a calm and focused mind.
Drawing well is a combination of muscle memory, dexterity, method, knowledge and mental focus. The most important of these attributes is the ability to focus, if your mind is not focused nothing else will work well.
If you compare the drawing that I did today with the drawings I did from a couple days ago you will see the difference state of mind makes. Today’s session was calm and enjoyable. The drawings arn’t perfect but a lot of them turned out well and I attribute that fully to my ability to focus and get into the groove.