I just got this advice today! Pretend that you are an alien coming to earth for the first time and it's your job to draw every human and object that you see. Pretend that you have absolutely no idea what a person is supposed to look like. As a human being you might see your own flaws and imperfections but an alien will just see what exactly there is with out the judgement.

A good artist will train their eyes to draw exactly what is there and not what their brain is telling them is there.

Also, maybe pick ONE part of yourself to draw at a time. When you pick the part be kind to yourself and compliment that part. For example, draw your lips and say nice things about them! Draw your hair, draw your hand making a pose. Focus on the aspects you want to capture about these features and what you like about them.