This spread is inspired by the work of Mimi Bondi, she posts tutorials on the YouTube. Her style is very intuitive, just begin with a basic technique and see where the page takes you.
She recommends using a limited palette. Start by spreading paint on your pages with your fingers. Let the first layer dry and spread some more paint. Once you’re happy with the background, move on to stencils or stamps. Then perhaps doodle, or add some text, or more paint. Repeat until you’re happy with the result.