I always hit old pillows. So I can't hurt myself. I realized as a child, that biting instead of hitting the pillow worked much better to channel my rage. Up to the point where the pillow was destroyed and I suddenly had feathers everywhere. Most annoyingly in my mouth.
A friend of mine once broke his wrist because he was hitting the marble windowsill with his fist in a tantrum. Afterwards he had to explain to everyone, how he broke his hand. How humiliating for him, but funny for all the others.
That was the reason my mother recommended the pillow method.
If you do have the space I recommend boxing a sandbag. But put some bandages on your knuckles first and do some low and high kicks hitting the bag. Very satisfying.
The method with breathing slowly and counting to ten never worked for me. Just makes me more angry. I have to let it out.
Nowadays I almost always keep cool. But when I'm really angry once in a while I have to let it out somehow. Don't need that sandbag anymore. A pillow is sufficient. And laughing in the face of anger sometimes works, too.
...And removing snow with a shovel, if snow is available.