1. Remove Your Shoes
Many yoga studios have a place for your shoes by the front door. Since people will be walking around the studio barefoot, it is most hygienic if everyone takes off their outdoor shoes first thing.
2. Turn Off Your Cell Phone
Make a habit of doing this as soon as you get to the yoga studio. You will be quite embarrassed if your phone rings during class. If this happens (and it has even happened to me), I advocate owning up and going to turn the thing off immediately. Some teachers prefer that it just be ignored and will let you know of their preference.
3. Arrive On Time
Arrive at least 10 minutes before the class is scheduled to start. If you do arrive late, don't enter a class more than 10 minutes late if it has already started. Wait for the next class or another day.
4. Respect the Teacher
When you enter a yoga class, you sign on to respect the teacher for the next hour and a half. You may discover halfway through the class that you don't care for this teacher, style, or hour of the day. But you still should continue with the class, follow the teacher's instructions, take your Savasana, and chalk it up to experience.
5. Keep Variations Appropriate
Keep in mind the level of the class you are attending. If it is an advanced class and some of the poses are too hard, it is fine to take a more basic variation of the poses being taught. Usually the teacher will offer this option. If you are attending a basic class, stick to the basic versions of the poses so you don't confuse new students. The teacher will offer you the option to take a more advanced variation when appropriate.
6. Go to the Bathroom During Resting Poses
It is fine to leave class for a few minutes to go to the bathroom: There is no need to ask the teacher's permission. The best time to go is when there is a period of rest, either in Child's Pose or Downward Dog. You will not earn your teacher's respect if you routinely dodge out during difficult poses or skip part of Savasana.
7. Don't Skip Savasana!
Your final relaxation in Savasana is an important part of your practice. Don't plan to leave class early. If you must, tell the teacher in advance and take a short Savasana before you go. Don't make a habit of this.