The general consensus of established artists is if you want to improve your painting skills the number one best thing you can do is to practice your drawing skills. So in that light, I have decided to keep my sketchbook handy and to spend some time each day practicing my drawing. Then when I look back, I can see how my skills have improved. I can already see an improvement over the past several months. I can draw faster and a little more accurately than I could before.
So I would encourage anyone wanting to get better at painting to first pick up a pencil.