I tried this today to loosen up a bit. With architecture and vegetation in mind I tried to think of a game that would give me a starting point for a painting, so I decided to start with some random shapes and then impose some kind of order on them. I was playing with the idea of straight lines with a reddish colour and wavy lines with a greenish colour.
It soon got out of hand but you can see the progression. The idea is to set some kind of abstract "rule" and see how far you can push it and transform it into something else. "Abstract" painting is a great way to let us see our own work for its visual impact rather than for what it represents.