How to perform the yoga asanas and what mistakes should be avoided – these questions are usually asked by people who have just started learning. But the answers, oddly enough, will differ depending on the person taking the particular pose.
Our bodies are different. And for each, there will be his/her first pose, created and discovered especially for him/her. Depending on your physical body condition, each asana will differ from the same pose for other people.
The primary criterion for the pose correctness is harmony, comfort, and pleasant inner feelings. And not a picture or a strict order, like an army statute. These instructions should be more like a mother's solid advice for you.
All instructions on performing the exercises, together with pictures, represent an approximate pattern, an approximate scheme, an estimated carcass. Don’t try to copy the image in all details.
Don’t force your body. Use your mind and common sense. Governed by these rules, you should take a pose approximately the same way as described in the instructions.
If you feel no harmony or have unpleasant sensations, for example, you can’t bend your knee too much or to take the pose ‘too much’, then don’t follow the instructions like ‘well, this is exactly what he wrote.’
This is only an approximate template. Take the pose almost in the way as described here, try to experiment and find your pose. Let your inner sensations help you in this!