Personally, whenever I need to control myself, I usually borderline act up first, before remembering how I want to behave. Just catching yourself right before you act is enough. Give yourself a reminder that a deep breath never did anyone harm, and neither did walking away from a problem or a root of whatever is making controlling your emotions so difficult. Avoid the issue, and if you can't, knock it down a peg by finding something you consider more important and worth your while.