Improve your darwing and painting - the value of the small sketch

I can't stress enough the value of working up a small sketch (thumbnail size 1.5 inch by 2 inch or more) in order to develop better paintings... even when you are working from life or outdoors Plein Air style.
Working small freely enables you to think about the very basic composition re: lights and darks, shapes and placement of major forms.  That is what was taught 'Old School'. Just using a 2B pencil or simple black wash you build a visual fluidity and eventually a rapid understanding of exactly what you are looking at.
Somebody said once "The sketch promises everything and delivers nothing "--- not so fast - It delivers plenty.

Here are a few small thumbnails by Mucha done on toned paper with a little pastel for some of his murals

These were done as background studies for a sci fi TV film proposal for a Hasbro toy

The next step is to bring up your idea to a more detailed small painting -about 3" x 6" - to work out the color and discover how much you don't know about your subject...i.e. more studies..definitely Old School