Some paintings are just one incarnation of one idea. There can be more.
Like these circle trees. The earlier one is quite small(40/50cms) and mostly blue, green and umber. After a while an idea grew to make a larger circle combined with the planetary view as it occurred in another composition. The idea of a circle of trees coinciding(or not) with other circular forms seemed inevitable. So the latest project is this larger painting showing red planets and trees.
Sometimes an idea comes up while painting another one. For instance when I was painting the small astronaut(40/50cm) the urge to paint a larger space themed painting became rather strong, so before the portrait was finished I had to paint the spaced rock arch(100/80cm). So really this shows how one painting can be the start of the next.