Power yoga was and is my first love when it comes to my own personal practice, but also teaching as well.
It is a heated practice that incorporates vinyasa flows, meaning we will be moving with our breath.
Additionally, it is a heavily modifiable form of yoga, making it accessible to most all levels of experience, body types, and levels of physical fitness. These modification options, I feel, really keep with the key ideals of yoga, in that there is no one perfect way to do a posture, rather, each posture can, should, and will look different with each person. As such, power yoga, with these modification options creates, a safe way to practice and grow.
When I teach power yoga classes, I actively walk around, providing options for modification, helping to encourage and ensure safe and proper alignment and posture.
One modificaion that people often neglect to consider, but I strongly encourage, is to ease off, or come out of a pose if it doesn't feel right, or if they need to take a different pose at that particular time. It is always to be remembered that it is YOUR PRACTICE, and as such, you are doing the right thing, when you modify out of a pose and perhaps take a child's pose or seated meditation.
The most imporant part of any yoga practice, including power yoga, is your breath. If you were to sit in a meditative pose and simply focus on your breath, maintaining deep and mindful inhales and exhales for the duration of the class, you will have had a tremendous practice and have gotten all that you need out of the class.
Leave your ego off of your mat, and just breathe and be. :)