Before you can train any Facial Expressions you need to train a Neutral expression. Your Neutral training will be used as a baseline to contrast with your expression training. During this Neutral training, the most important thing is to relax the muscles of your face. You can let your mind wander in any way.
To train a Neutral expression select Neutral and click on Train button that appears to the right of the command box. You will then be asked to hold a Neutral state for 8 seconds. During this time you will see a face with no expression.