It's not that hard, and a particularily useful thing to do. This little meditation technique can relieve you of stress.
The trick is to seperate yourself from your mind and become aware of your Being in the here and now. Start by getting into a comfortable position (crosslegged if you wish) and become aware of your breathing. Breathe deeply and slowly. Now, take an inventory of your senses. Start with touch; notice the strange feel of clothing covering your body, notice the texture of the fabric, and the way it lays on your skin. Notice the currents of air as they move about you. Now, listen. Notice the slight background sounds; like air coming from air-vents, the 60Hz hum of electrical devices, faraway conversation, or the wind in the trees outside. Finally, look closely at your surroundings. Examine the interplay of light and shadow, the organic and geometric forms of the things that surround you.
The idea here is to become intensely aware of your environment. Fear and regret come from the mind. Your fears exist in an unknown future, while your regrets exist in the past. However, you exist only in the Now. If you can truly become aware of this, your stress will vanish, and your mind will become clear.