I am what you call a Daily Painter, (my main website is on Dailypaintworks.com ). An often people assume I do a finished painting every day...nope. What daily painting means to me is, working towards a painting everyday. Often I do cartoons, a great way of getting a feel for the character of a subject. Sometimes I do black and white sketches, with ink or charcoal, to understand light and shadows, mass, and line.
It is all part of the process, that I love about art.
Draw, draw, draw important advice to any painter. This loose painting of cats, (what my cats actually do most of the day) started with a number of drawings. Quick charcoal sketches help for getting to know your subject and for planning a composition.
my easel with reference drawings
After doing about a half dozen charcoal drawings of various cat poses, I picked my favorites and used them for reference while painting. My models do not sit still for very long, so quick drawings, (lots of them) really help me to capture posture, and the attitude of each stance.
I also use black and white chalk, to create an abstract of what I plan to paint, this is extremely helpful for planning the basic composition. With this step I am not trying for any realism just light and dark contrast, and line movement.
So when ever you have time grab a pencil, or charcoal stick and sketch. You never know what those sketches will lead to.