Bound Angle Pose is a great way to open your hips. It’s safest to do this slow with comfort. Some people may try to overexert themselves. Some teachers may also try different methods. For example, I met a martial arts teacher who would have students stand on each other’s femur while they were in this position; their logic led to the use of gravity to pry the tight hips open. This is a different methodology from the methodology I recommend.
The method I recommend involves opening the hips in a comfortable fashion. It’s not a race and there’s no end point we have in mind. Consciously tell your body that it can go further, and if you hear it tell you that you’ve gone too far – respect it and go back a few degrees. If you listen to your body and let it explore in a manner in line with its programmed tolerances, over time you’ll have a lower chance of injury and feel more connected with your practice.
Focus on keeping your pelvis in an anterior tile. Sit on your sit bones. Go forward before going down. Head-to-Knee can be transitioned to by extending one leg forward.
Head-to-Knee Pose is similar to Dandasana except one foot faces your thigh. Only go into spinal flexion if you can safely and comfortably come to 110 degrees with a neutral spine. Be sure to keep your pelvis straight; it can be tempting to open your pelvis by way of moving your flexed knee back and front foot forwards, try to resist and rather stay up straight and save flexion for another day. If you can’t come to 110 degrees, focus on moving your chest forward rather than down.