With a full mask don't use a mirror, but half masks can benefit from one. Keith Johnstone's chapter on masks has been brought to life by mask teacher Steve Jarrand. You can see the pair of them on the DVD 'Trance Masks' There is an extract on youtube (see my playlists 'Masks') which shows in a wild & chaotic way how mirrors are used to help sustain half mask characters.
@ROPERBOYUK Well, you can play them with a different emotion. And that is often necessary when you are working with them. The trick is to let your body play the different emotion. So, for example you can have a 'happy' mask with a 'sad' body. If you want to practice this then try (without any mask on) walking across a room with a happy smiling face while the rest of your body is sad. Its weird but fun to do.
Yes - always turn away from the audience when putting on or taking off a mask. If the audience see you face on doing this, then it spoils the illusion. Also, never wear a mask on top of your head like a hat! Very tempting, but try to resist it.
You have shattered the illusion by putting the mask on in front of the audience. When using the mask in profile, the eyes can't be seen. This is the main reason for the mask dying. The same happens when you look down or up too steeply.
