Use a grid when painting from a picture
I had the opportunity to go to a buffalo conservation in Montana. I took photos of amazing animals–buffalo, sheep, elk, deer–all in their natural habitat. Naturally, I went home wanting to paint a picture of a buffalo. My mom gave me a black canvas to paint, and I sketched out the outline of a buffalo from a picture I had taken. The buffalo looked more like a pig.
After some convincing, I finally gave in to my mom's tips on making a grid, and sketching the buffalo piece by piece. The results? A buffalo that looked like a buffalo. To do this, divide your picture into a grid, and enlarge that grid on your canvas. Draw out each section of the grid (rather than the entire picture). This will ensure accuracy in proportions. The smaller your grid increments, the more accurate the drawing. Once you have your photo in sketch form, then start painting in the colors and the details.