A quick black-and-white sketch
A sketch in full color with minimal light/shading. I do these a lot!
Either a fully colored sketch with detailed shading, or a fully colored digital piece (with or without shading, depends on what you want). No background.
Full Color + Background
A fully colored piece with shading and a simple background. Less common in my gallery, and takes me a bit longer than the others.
Color + Big Background
A fully colored picture with a fairly complicated background. (A nature background like this will look better than buildings, by the way.)
FYI: These take me the longest. I put the most effort into them.