Here’s a tip for oil painters. Buy lots of brushes in your favourite sizes so that you can wait till the end of your painting session to clean out your brushes. It takes a lot of time and energy to properly clean oil paint from a brush. Better to set it aside on a paper towel, and grab a fresh brush when you change colour. That means the you can keep with the flow of the painting and leave clean up till later. Otherwise, you run the risk of not completely removing the colour as you continue on. Even a small amount of a complimentary colour left in the brush, can muddy your paint. Keep it fresh!