A simple and very relaxing way to practice letting go is to regularly take some time for nothing!
You do nothing for 10 minutes. Sit or lie down on a sofa, close your eyes and then, relax. Come to rest. Relax your body. Let your thoughts flow.
In the beginning you may have 100,000 thoughts running through your head, allow them to say to yourself over and over again for 10 minutes just lie there. Thoughts come and go. If you let the thoughts come without any evaluation, they will go away.
The more often you do this exercise, the easier it will become.