You would be surprized what effect even keeping a small smile on your face does for you.
In hard times under pressure it can trigger brain waves that relax you more.
I think its also disconcerting to someone who is trying 2 beat on you ,to see that you are emotionally uneffected by them.
Relax by knowing that you dont ever move into trouble.
Know your footwork by practicing your work with things in yourmind as to WHY?.
Know exactly why it is ,that you move a certain way.
Study the others moves from a distance when they spar someone else ,look and know where you can go to get away from their intentions,move away from their largest threat ,catch them on the turn.