I think it is less important to keep it in check, and way more important to find out why it makes you feel that way. When I have anger or any negative emotion going on for a while, I always take the time to ask myself what's going on. What would I have to believe in order to perceive anything this way? It is extremely revealing and it is helpful in finding out where we perhaps have a flawed perception of things, and where we have limiting beliefs that don't serve us.
What I often notice is that I tend to take things personal which could easily have nothing to do with me. For example, when my son makes a mistake and I'm the one stumbling into the mess, it is easy to think he did it TO me, but most of the time, he might not have thought a thing and just did it out of negligence or lazyness. And in all of these cases, my anger and my negativity show me very important information about myself and give me the opportunity to adjust my own perception of the world around me.