Paivi has a tutorial on that. It was where I got the idea to spend some time with a blank mind and just get busy with my paints. So many things going on in my mind that I decided I needed something simpler and where I didn't need to think.
It is so easy..... A watercolour background, doodles and more doodles and more paint or coloured pencils and then you have a wonderful paper to use for collages or wrap a present.