"Tapping" is a very easy technique you can use for
Quick calming/focusing
Releasing emotional reactions
People also employ it for:
Releasing phobias
Boosting confidence
Finding and resolving emotional triggers
Addressing emotional eating
Reducing anxiety
Managing emotional reactions to physical pain
Tapping has been so popular that there are many spin-offs. The original and "gold standard" technique is free to learn here.
If that's too much to read at first, simply tap with your fingertips each of the points above, from the top down. You will be able to notice a calming and centering effect.
Tapping is a well accepted technique for deep healing, so delving into the site and the technique is well worth your time and effort!