You will find it uncomfortable to do a yoga practice after eating a large meal, so wait for about two hours before starting a practice. If you want to practice but feel very hungry, eat a piece of fruit or other small snack.
Stand or sit and become aware of your breathing at the beginning of each practice. Reflect on your inhalation and your exhalation until each is smooth and regular. Try to keep that awareness and smoothness throughout your practice.
Use your breath as your teacher. When your breath becomes forced or uneven, your teacher is telling you to rest and wait for your breath to recover.
When your attention wander during practice, gently bring your attention back to focus on your breathing and the movements of your body.
"Feeling irritated, restless, afraid, and hopeless is a reminder to listen more carefully" - Pema Chodron