Deep Breathing. You don't need much time or expertise to try deep breathing. Just focusing on your breath and expanding your lungs with each inhale will deliver more oxygen to your body and help you relax. Try this technique: Sit in a comfortable chair and close your eyes. Breathe in for 1 count, out for 1 count. On the next inhale, breathe in for 2 counts, out for 2...continue adding on until you're up to 8 counts in and out and then pyramid back down to 1 count.
Meditation. Many people are afraid to try meditating, thinking there's some special way to do it. The truth is, meditation can be whatever you want it to be. All it requires is mindfulness. To get started, try this Meditation 101 e-course or one of my favorite tools, Kelly Howell's Guided Meditation.
Yoga. Yoga is a kind of moving meditation, helping connect your breath to your body. You can try this short Gentle Stretch workout, this Morning & Evening Yoga Routine or this Relaxing Stretch on the Ball.