Reading your body!
Your body is constantly sending you cues, letting you know what works and what doesn't, but if your not listening you'll miss these signs and possibly deal with negative repercussions. Yoga is all about the balance of ease and effort. If you feel your body straining, if you notice your breaths are shorter or if your holding your breath, than you've most likely gone too far for your body at the present moment. If your quick to hit the mat getting out of a pose, (which is just as important as getting into them) perhaps you needed a slight modification (even if its just for that particular day). It's amazing that you've finally mastered wheel, but if you abruptly drop to your mat afterwards, your losing all the beneficial value of the asana. You need to exit each pose with the same ease and grace you used to get into it.
So, remember to go easy on yourself. Everyday is your first practice. Live in the now and accept each pose as a successful step in the direction of healthy yoga lifestyle.
Hope these tips are helpful!
See you on the mat =)