How do you relax your mind?

I don't know if the mind can be "tamed," but to relax it, meditation works well. And it can involve just sitting with your closed eyes for 15 or 20 minutes, reciting a mantra or not - or, by watching a river or stream or sitting by a lake, watching the birds fly by, sitting in front of a nice fire in the fireplace.... lots of ways. And if you find it hard to let go of worries, you can visualize taking them out of your head and putting them in a jar, then putting the jar on a shelf and leaving it there for the time you're in meditation, knowing after your meditation, you can put the thoughts and worries back inside of your head. But let it be okay that they're not inside of you, just for the time being.
Just drop all resistance and think of nothing. When thoughts arise (and they will), picture each thought, regardless of what it is, turning into a cloud above your head and blowing away behind you. Good Luck.