When you do yoga asanas, don't try to force your body into an "ideal" position; instead, do them from the inside out. Move into the postures with inner awareness, noting and accepting your body's strengths and limitations. Don't worry if you can't stretch as far as someone else—yoga is about doing the poses the best you can while maintaining proper alignment. This is the safest way to practice, too. If you practice regularly and conscientiously, gently stretching your boundaries, you will advance very quickly.