Paint what you see and look with your own eyes.

I copy the works of God, and leave clothes to tailors and mantua-makers.

What a business is this of a portrait painter! You bring him a potato and expect he will paint you a peach.

When I painted him, he had just had a set of false teeth inserted, which accounts for the constrained expression so noticeable about the mouth and lower part of the face. - speaking of George Washington