I frequently do acrylic painting exercises on an inexpensive canvas. I typically will work on a 16 x 20 size and buy these in bulk from a craft store. All of my paintings begin this way: play mode. It is important to get started, to make some marks. A blank white canvas can be intimidating.
I mix all of the paint first because if it isn’t on the palette already, I tend to get lazy and just use what is… mix more than you need and use it all. My palette is created with damp paper shop towels laid out in a baking tray with tracing paper on top. This will stay workable all day. I mix all of my paint with acrylic matte medium. At this point, I am only using black and white.
As I continue to paint different layers – still playing with no planned composition – I have added some color to my palette: burnt sienna, yellow ocher, and ultramarine blue. I often paint many subsequent layers.
In the final layer, I have begun to experiment with dark and light areas, also some loose color mixing. burnt sienna and ultramarine make a beautiful black that I use frequently in my paintings.