Studies for bigger painting of the same subject with my students. I even made them do a graphite drawing to start with. This way the final painting was easier and looser, as they by then knew better the subject and how they wanted to paint it. A process that surprises most as they think you just start painting, without any thoughts of how you are going to proceed or what you want. The amateur gets saturated of the subject very fast. I can only explain this by a not yet developed insight in the subject or the different knowledges you need to paint and a lack of looking. Knowledges that make the process interesting.
Think you have done it all and your best after painting a subject once, when you can paint it a hundred of times without doing the same thing and only get better and better.