Adho Mukha Svanasana (Downward Facing Dog)
If you just have time for one pose, downward dog is my recommendation. This pose is a superb shoulder and back opener, and is also excellent for the hamstrings, calves and Achilles tendon.
Start on your hands and knees, with your knees directly beneath the hips and hands slightly in front of your shoulders. Exhale and tuck your toes under, pressing your tailbone toward the sky. Keep your knees slightly bent to start. Press your heels toward the ground; it is okay if they don't reach it. Broaden your shoulder blades away from each other. Spread your fingers on the mat, using your whole hand. Breathe deeply and hold for one to two minutes.
Parvritta Trikonanasa (Twisting Triangle)
This pose is wonderful for balancing out your backhand and your forehand side.
Stand in Mountain Pose. Step your right foot out about 3 to 4 feet.. Angle the right foot out 90 degrees and angle the left foot inward about 45 degrees. Place your right hand on your right hip and lift your left arm straight up. Exhale and keeping your hips as square as possible, reach up and forward, hinging from your hips as you twist and draw the left hand to the outside of your right calf or ankle. You can also use a block here, placed next to the right leg and place the hand on it. Allow the left hip to drop forward slightly. When you can't twist any further from the waist, extend the right hand up. You can either gaze downward or if you are comfortable here, gaze up toward the right hand. Remain in the pose for 30 to 60 seconds. Inhale back up to standing and repeat on the other side.