In general, it is important to repeat exercises for the same amount of times to each side, to keep balance in the nervous system.
While doing any yoga, it is a good idea to loosen your belt, perhaps even unbutton your trousers, so the airflow is not obstructed. Keep your back straight and relax your shoulders. Inhale through the nose, slowly and steadily, focus on getting the breath all the way into the belly and then slowly exhale through the nose. Keep your lips closed, to avoid hyperventilating. If your mind starts to wander, simply bring your attention back to the breath.
For seated poses, keep your feet firmly planted on the ground, with your knees bent at a 90 degree angle. Keep your back straight and rest your hands on your lap.
For each pose, please notice wether you are to sit on the edge of the chair, or all the way back in the seat. This is important to prevent the chair from tipping.