To me, what is important in the book of Betty Edwards, are not theories about the brain (those who are not interested can read diagonally), it is simply effectiveness. No need to be convinced by the theory, simply follow the exercises and tips and you start to magically draw what you see AS you can see, with a real likeness. After learning to observe (this may be fast, a week's holiday for me), it remains only to practice to acquire more ease. But it's a real release feel that we are no more, the door is open. Make it the beginning of the test designs, especially for the self-portrait, to measure progress in the end. It is striking! Please note that this method does not make you a pro can chew anything in five minutes to draw pictures absolutely perfect or realize imaginative designs. For this, we must continue working. But it allows all those who drew badly and / or with great difficulty, draw very well with lots of fun.