When I do a "true" painting, not mixed media, I work exclusively in OIls. I paint in the tradition of the Old Masters, gesso, pencil or oil wash sketch, washed in under-painting, and then the final paint. I love the "feel" and brilliance that can only come from oil. It also smells good.  I work almost 50/50 on canvas I stretch myself or canvas board.  A lot of factors go into this decision, none of them really rational. I also paint in a variety of sizes, from large paintings, 3 x 4 feet to a small 8 x 10 inches. I started painting very large early in my career and I seem to be painting smaller as I get older. I also seem to be getting dumber. My wife, Laura, is the model for all my female characters, my friends reluctantly volunteer for the male figures, and some I just make up.