Go outside, preferably to a park, river, ocean, or whatever you can get to, even if it's just your yard. Exercise your senses. For instance, look at the trees, grass, plants, whatever is around. But really look. See all the different greens, the gray-greens, the yellow-greens and so on. Look at the color of the earth. See the different shades of browns and reds and yellows. look at the texture of it. See the pebbles or bits of leaves.
Kneel down and feel the dirt and the grass. Run your hands along a tree trunk. Feel how rough or smooth it is. Really concentrate on the sensations in your fingers. Feel the air against your skin. Is it warm or cold? How warm? How cold? Can you feel the sun? What sounds do you hear? Is there a breeze? Can you feel it or hear it rustle the leaves or the grass? Are there birds singing or insects chirping? Really hear the sounds around you. Now what do you smell? Smell the earth, the growing things... Really concentrate on what they smells like. Open your mouth and breath in deeply. Can you taste the grass in the air, or a recent rain? Can you taste the cold or the heat?
Now close your eyes, feel the life around you. Feel the insects going about their business, feel the wind. Feel the trees and the grass drinking in the sun. Feel yourself, the blood in your veins, your heart beating.
You can spend as much time as you want on this exercise. It's a good way to get reacquainted with the world around you. Of course you'll be experiencing different things if you go to a beach instead of to a park, but the above is just a guideline. The goal is to exercise you senses and become more aware of what many of us take for granted everyday (our senses and the world around us).