I have officially started the clapboard application. I started on the kitchen bay window, as that is the most straightforward, with absolutely no angles or windows making it more difficult. You can see in the pic that I am lining up the pre-painted (two coats) boards with the pencil lines.
Then I moved on to the right wall. This has an inside corner to be trimmed each time, and now I am just starting to sculpt boards to fit around the stair window. I realised that I need to paint a little ring of green paint around all the elements, just in case I leave a tiny gap that you can see through when trimming the boards. I am snipping my clapboards with a hand-held cutter (like garden shears) that is sold by hobby stores, and using an X-acto knife for complicated cuts.
I think I am going to be doing this for a looooooooooong time.