beneath
When I played catcher for a fast pitch softball team, the pitcher always had to warm up before the game. The first pitches could be pretty wild and over my head but the more she pitched the more she burned them right into my mitt. I’ve notices when I sketch, the same thing happens. The first few sketches are not quite there but the more I sketch, the more my eye and hand and brain seem to work together. So I guess it’s also a good idea to warm up a bit when you are sketching. You can sketch from real life which gets your observation skills working. You can sketch from your imagination which is a great way to warm up your creativity. Illustrations end up being a combination of both reality and what is in your head. We shouldn’t be afraid of the sketches that are made before we warm up because they lead us to where we want to be. The sketch book becomes a great place to preserve both types of sketches for future use in an illustration. Was the above illustration from reality or my imagination? Or was it a combination of memory, reality and imagination? No matter where it began, I discovered it in my sketch book.
SherryMeidell'sTeetertotterTales 
Sketchbooks, and for me, notepads, are surplus for the brain, treasure troves for future ideas and insights, that would have otherwise be lost, but that we capture before they slip away.