Clothing no-no: supershort shorts or loose shorts
Issues: Shorts are perfect for sweaty runs or strength training at home, but not for yoga class. You want to feel confident that you're completely covered when doing poses where you're bending forward or sticking your leg in the air, and the last thing you want to think about is whether or not someone can see your private business. Short shorts and loose shorts also tend to bunch up when you move, and you can do without the distraction of having to pull them down every five minutes.
Do wear: Go for fitted cropped or full-length leggings. Not only is your booty fully covered, but the material hugging your legs will also absorb sweat, giving you traction to do arm balancing poses like this.