Two years ago I drove to Seattle and stayed with my son and his wife and my grandson Caille's home. They had a painter prime and paint the wall of his bedroom in preparation for a pirate ship mural. We went to the library and checked out several books on ships and pirates and planets.
Then I made some sketches and got a few supplies at Michael's Crafts. Caille and I spent a couple of days sketching the design out and he helped with his own drawings behind the door.
Then using a mostly monochromatic color scheme we painted the details and then embellished the sky and edges with a sparkly dimensional paint. It turned out very cool.