I put the picture on the ground in the sunlight. I stand over it and shoot straight down. I just try to align the edges as squarley as possible, becuase I will crop it.
When I get inside, I download it and get it into Photoshop. I crop the picture, just looseing the slimest edge.
Then I put the painting next to my computer screen, and I tweek the saturation and the colors until it looks like the real thing.
Then I save it under "file_name improved". Then I resize it about 8x10 for my blog and save it "file_name improved 8x10", Then I size it again at 500 pixels for Wet Canvas and call it "file_name improved wc". Then they are all right next to each other in my file, and I know what each one is.