Block out the composition
I scan in and place my paper sketch as the uppermost layer, setting it to Multiply mode. This enables me to follow the original concept closely, and means that I won’t have to recreate every element from scratch. However, I’ll use several materials to establish scale, and use references for details and realism. I plan to have a statue in the foreground, and also introduce architectural elements such as viaducts and large domes in the background, so I look in my personal photo database for these kind of elements. While referring to my original sketch I’m aware that I need to maintain a consistent perspective when placing my chosen elements in the composition.