Teach them to work through their fears till they reach the answers ie competitor analysis. Fear can shut down the mind and put any technical knowledge outside their reach. Fear also affects decisions and chess is about making decisions. Fear is also the enemy of ideas and chess is about ideas. And as I have said before, the source of fear is the ego. Read this too to see if you agree. Here.
Note: This is what I said at the last FGM Thematics. There is no pressure if you are playing against a known technically inferior player. The perception of fear begins when we meet our equals and above, when we think we can lose. Then the use of competitor analysis helps us to ground ourselves and choose and prepare the weapon that gives us the best chance. And so we fight with realistic expectations. A lessening of fear. A winning edge?
There is little fear in most of our U12 and so they can fight well. After that age more and more fear creeps in and that eventually cripples their game. If that is the case we need to examine fear and its causes. And in chess, I have stated that most of our fears are imaginary. Does this make any sense?