Art is not something that just happens. There is a process involved otherwise you would have a lot of truly terrible paintings ( not to say that doesn't still happen sometimes). The actual laying down of colour is the culmination of all the planning. The drawings, working out the mechanics of how you are going to lead the viewer into the scene, colour pallette, light and shadow etc. For me that means thumbnails, small sketches with notes and instructions.
Then marking and laying out the canvas or in this case wooden panel to get the structure and foundation of the painting critical to the process so that by the time I get to actually applying the colour o an sure of where I'm going and can get to the fun part without worrying about layout and composition problems. And you thought painting was intuitive!!😉