Although staring at a reflection of yourself can feel uncomfortable at first, using a mirror is one of the best ways to achieve the realism you desire. Here are a few tips to help you capture your own self portrait using mirrors:
Position it close - Set up your mirror at any angle you like, but keep it close to your drawing surface. You’re looking for a pose that feels comfortable and natural so you can maintain it for several minutes at a time.
Hold your place - As you look into the mirror, draw a red dot in between your eyes on the mirror, so you can return to your original position if you move. You should note where you’re sitting as well. A little masking tape or painter’s tape to mark the feet of your chair allows you freedom to get up and move about.
Take a snapshot - When you have found a working facial expression, take a snapshot. You may need to refer back to this original pose later on. A friend can help you capture the expression.