The body scan is a good, simple meditative technique than can be done any time of day, but is especially beneficial at night, if sleep is elusive.
Lie on your bed or comfortably on the floor. Try and relax all your muscles. Inhale and exhale slowly a few times.
With your next inhale, imagine that you are inhaling healing breath all the way into your left foot. Have your attention follow the breath into your left foot and observe all the sensations that arise in your foot. As you exhale, imagine you are ridding your left foot from any toxins that have accumulated. Take 3-5 breaths into the area of your left foot and slowly have your attention wander up your left leg. With each inhale, imagine your are bringing new energy into your left leg. Observe for tensions, and if you can, release them, let go. Once you have come to the top of your leg, move your attention to your right foot, inhale a healing breath into your right foot, then leg. And again, with each exhale, exhale toxins and stress.
Then move your attention to your left hand, continue the slow process of inhaling and exhaling and attaching your attention to your breath as it wanders through your left arm. Then do the same on the right arm.
Then move your attention to your back, initially the lower back, feel the weight of your body against the sheets or floor, feel the sensations, the pulsing of your breath and the vibrations of your heartbeat. Try breathing into your lower back, then the lower lungs, then the shoulders.
Now mover your attention to the front of your torso, feel the rising and falling of the abdomen with each breath. Imagine again, that you are inhaling healing energy and exhaling toxins. Slowly move your attention up to your heart area, feel your beating heart, notice any other sensations in your chest. Remain here for several breaths.
Then focus your attention on the back of your head. Breathe into the back of your head, your ears, breathe slowly in and out. Then take your attention to your jaw. Do you notice tension? Try and release your jaw. Try and release your facial muscles. Breathe healing energy in and toxins out. Then move your attention to your eyes and forehead. Try and relax both. Stay here for a few breaths. Then move your attention to the crown of your head. Breathe into the crown of your head, and imagine you are able to exhale through the top of your head. Breathe in and out through the top of your head, and imagine that you are taking in healing energy from the universe through the top of your head, and imagine that your exhaling breath mixes back with the endless amount of breath and life that is always around us.