The first niyama, or observance, of yoga is called Saucha, a Sanskrit word meaning purity. Purity can be about physical surroundings, our minds, our bodies, the food we eat, etc. When we think about it in terms of our surroundings, we begin by looking at clutter and cleanliness. When our space is clean and free of clutter we tend to think more clearly and our minds are more peaceful. Some tips for decluttering can be found here: http://zenhabits.net/zen-mind-how-to-declutter/
Saucha also takes into account the purity of our thoughts, words and deeds. It’s not about judging a person or our world as impure, but rather ensuring that our thoughts are harmonious with both our intentions and the world around us. Letting go of relationships that are sustained through gossip, sarcasm or other habits that affect the purity of our minds is a way to practice saucha. While this can be very difficult to do, especially when letting go of a long time relationship, it is important for your mental health. If such a relationship causes you to behave or think in ways that don’t align with who you want to be, you will likely experience some sort of inner turmoil. Ask yourself why you are attached to this relationship. What are you getting out of it? Judith Lasater, a long time yoga teacher, suggests that “If you embrace impurity in thought, word, or deed, you will eventually suffer”. If you surround yourself with people that are positive and kind, you’re more likely to have purity in your thoughts and deeds. It at least sets up the circumstances to support saucha. We all from time to time think negatively. Wayne Dyer has a simple technique to stop the cycle of this sort of thinking: whenever you have a negative thought, just say ‘next’ and move on.
When in asana class you can practice saucha as well. One way is to come to class with a clean mat and well-tended body (clear of impurities). Also, clear your mind before class. This can be done by centering, meditation or prayers before beginning. Often your yoga teacher will do something at the start of class to help with this. Another way to practice saucha during asana class is to fully exhale, ridding the body of more toxins. Of course, the asana practice itself will help with this too.