Chin-Cheng Hung teaches foundations and drawing courses at the Savannah College of Art & Design. Very accomplished, students know him well, some fondly, because of his outlandish comments and suggestions. For example, "You don't know who Norman Rockwell is; you kill yourself." Or, "You come to drawing class with no pencil; you kill yourself." Or, "Pretty good...if you're twelve year old."
I love (in the sense of learn from and want to iterate) these statements because, fact is, art students should bring a pencil and know about Norman Rockwell. Also, it points to the following; you really need to draw to make any good pictures, painted or other. You'll need a pencil for that.
In other words, and, in general, working without a plan, being unprepared...you kill yourself.