Make it a habit to arrive early. Nothing disrupts a local class mood like the late comer. You need time to set up your mat, get yourself situated and be ready to begin. If you must arrive late (because sometimes life happens) come in as quite as a church mouse and set yourself up and get settled as quickly as possible.
Wear decent clothing
And by decent we really mean non-revealing. Be mindful of the other students. Please wear clothing that will not reveal your private parts in full (or partial) glory to your fellow student when you are upside down or in some twisted pose or drenched in perspiration. Attracting this type of attention in class is most definitely frowned upon, no matter how attractive (or handsome) you may be! Our dress code is just as much for the other students as it is for you.
Mind your personal hygiene
Remember class is often a very intimate setting and you may practice closer to your fellow students than you prefer due to lack of space or a crowded room. Use Deodorant. Use toothpaste or mouthwash. Wear clean clothes. Bring a clean mat and clean towel in. Do not wear cologne or perfume.
Some people arrive early to meditate or simply turn their focus inward. Keep your conversations to a minimal or in hushed voices.
Turn off your electronics
Ringers and alarms are distracting- even when left in the lobby. If you must keep your phone near you please advice the teacher of your situation.
Take off your shoes
Classes are on a hard wood floor. Everyone practices bare foot. Please leave your shoes on the black floor mats in the studio.
Respect the teacher
Respecting your teacher comes in many forms. The easiest one is following the poses or a modified version of them. Do not do your own series in the middle of a guided class if you are bored or uninterested in the current pose. Finish the class and choose another teacher but during the class, respect the teacher enough to follow instructions and do so with an open mind.
Observe silence during Savasana (final relaxation)
This is one where you will know and love when you have made friends with your yoga but it will take time. Until then, consider it a dedication to the finish of practice. Practice silence during savasana and however tempted you may be to leave and skip out, resist it. This is where your practice assimilates and the results are infused with a repose so well-deserving and so necessary. If you must (really must!) leave before the end, leave before people settle into savasana and be as quiet as a church mouse!
Clean your Immediate Area
If you borrowed a mat from the studio, wipe it down. If you created a puddle of sweat, wipe it with your towel. If you used props, spray down and put them back.
Story derived from http://www.prolificliving.com/blog/2010/06/22/14-yoga-etiquette-tips-respect-your-fellow-yoginis/