Meditation is great, once you are good at it, it's like a vacation in 20 minutes.
Here is a simple Visualization that works well in only a few minutes.
Sit quietly in a chair or if you can lie down.
Breath deeply and slowly
Close your eyes
Imagine the clock in your mind, it can be any clock you wish.
Now while you are breathing deep and relaxing watch the clock in your mind as it moves forward 1 minute, 10 minutes, 1 Hour or 2, however much time you feel your body needs to relax. Once the clock has reached the time you feel is right, open your eyes and feel refreshed and awake.