Here's a breakdown of how I did the 10thology pinup.
I based it on an old sketch. I scanned this in and quickly worked up a background in Manga Studio. Using the concentric circle and one point perspective rulers this was a doddle. I printed the whole thing out in a light orange as I wanted to try and replicate my sketchbook style and see if I could take it on to a slightly more finished look. The drawing went quite smoothly but I messed up the face a little. I drew a new one and patched it in in photoshop. I also went back to Manga Studio to do the spaceship. I set the greywash drawing layer to multiply and coloured underneath. I didn't add the spaceship till last and coloured it on a new layer.