these are few techniques which i found useful,
1. when you really get angry on some thing or some one, take few deep breaths (real deep, you should start breathing from your abdomen).
2. keep saying a relaxing word to yourself (like; its OK, relax, cool it, alizwell etc.)
3. picture a beautiful scenery or a relaxing moment from your memory.
another option would be to avoid such situations, but most of the time it becomes unavoidable in today's busy world.
have you ever looked in the mirror when you are at the top of your anger? try it next time.. and picture that face of yours each time you feel angry... that could be a game changer for many.
suppressing your anger is not a good option, as it might lead to psychological disorders like hypertension or depression.
so get angry, get mad, get craazy... but control it, take the flow in a different channel and find out how peaceful your life can turn into.