|16 X 20 oil on board "The Forbidden Fruit"|
To use the mistake process you must first know what it is you are trying to do. Saying that you want to create a beautiful picture isn't enough. This is a type of goal and the more specific you can get the easier it will be to learn, grow and get better.
So for example I'm working on Plein Air paintings. My current goal is I want to paint paintings that are warm and friendly, eye catching, strong tonal and temperature contrasts and simple brush work with an easily defined focal point.
Every time I sit down and paint I'm going over these goals in my head. I'm making choices based on them. Also I've learned that once you put down a stroke don't go back and fiddle with too much. Be confident in your brushstrokes. If you fiddle with the brushstrokes too much you'll just end up with a muddy over worked tired looking painting.
Once the painting is done enough, it's time to compare it to your goals. This is where I perform a kind of autopsy on my painting. The key to this part is asking questions. Your brain will in time find the answers. So start asking. Why did or didn't it work? What could I do next time? What goals did I get close to and why? What artist that I like are able to achieve the goals I've set successfully? What is the difference between their painting and mine? Then sit back and ponder. This is just giving you brain time to find the answers.
Once you get an answer then you may want to further refine your goals or go and do another painting, repeating the whole precess again.