I'm generally a very happy person, and I've become so much more patient with others over the past couple years. (This is mainly because of problems involving my middle sister and parents that I have no control over.) I've grown to realize that I can't lash out at people because I feel angry or hurt from issues they have no control over. And I've also realized that everyone gets angry and upset with everybody, it's human nature.
Even though I've always naturally been a non-combative person (raise the roof for Sagittarians!!), I do occasionally get upset to the point where I don't want to talk or deal with anyone, even if they're my best friend and have no idea that I'm upset and/or why. What I tend to do is just shut the door, turn off my phone, sit in silence on the way home from work, walk through a mall or park before I go home, etc. and not talk to anyone until I return to my normal state of happiness. I'll even tell my friends and family that I'm feeling grouchy or angry, or that I need some alone time, and I don't think it's best to talk or do anything until I feel better.
If it's something that I absolutely need to get out of my head and off my chest, I'll call up one of my two best friends and vent out my anger with them. And if they're not available, I'll call up one of my grandmothers and talk to them.
I find that these two ways (the former more than the latter) really help me to cope with any anger I feel at any time. And of course, who can deny a nice long nap if there's time??