I recently have gotten into the practice of composing my more complicated images digitally before going to paint. I took a page from the book of Jesper Ejsing, an artist I admire who uses this practice to his advantage. The first image is a combination of some drawings I fleshed out with a paper and pencil traditionally, threw into Photoshop, and then arranged with background I sketched in digitally.
I’ve found that this allows me quite a bit more freedom with my composition than trying to sketch the entire drawing on a single piece of paper. There is no hesitation with moving or resizing the disparate elements, no hesitation caused by having to use an eraser to make changes. When I sketched my ideas completely traditionally, I tended to erase and move things so much that the tooth of paper completely died and the eraser dust formed a fine layer on my work surface. Now it’s a clean file on my computer.
I used to really abhor any use of digital methods whatsoever. Of course, this is all preliminary detail- I still have a finished oil painting at the end, the methods I use to get there are just different. My new philosophy is: if it works better, use it!