I finished today two studies of ACEO size, "Girl playing with a kitten" and "Blondina" by Lord Leighton. Studies are like talking to Masters. They give you valuable advices - what colors to use, how to relate values etc. You may not listen well, then you make mistakes in studies (as to me, I do them often, I am not perfect student). But you learn anyway, little by little. When I see my old paintings I see my mistakes more clear, I would never see them, if I will not learn with every my painting.