Marichyasana B is also a wonderful pose. It prepares for the legs behind head series like marichyasana A. Here too, when my one hand has reached the wrist of the arm, I stretch both arms and then I move forward into the pose. This allows to go deeper and to use the arms as a leverage.
The longer one practices the more one also must learn to learn on one's own. Teacher might move, classes might be overcrowded and beginners need the most attention. One can indeed learn to learn.
Here are a few of my favorite ways of learning:
1. I search youtube videos. My fav online teacher is Laruga. I look how she's doing an asana/vinyasa and then I try to imitate it. This has changed my practice already for the better.
2. I take pictures of myself. Filming would be even better. A pose looks differently than it feels.
3. A lot of books are available with great tips.
4. I check my breath via a watch, inhaling shall be as long as exhaling.
5. Sometimes I practice with the CD of Sharath. It helps me to find an even rhythm, it helps me not to take these little breaks between the asanas. I also hold some poses as long as it is supposed to be, headstand at the end i.e. When I practice alone I'm too quickly bored here and I move on.
6. Repetition, repetition, repetition......is always best advice.
7. Developing a positive attitude.
8. Eating well.
9. Writing about the practice.
10. Having measurable goals with a deadline. Even though I think it's equally important to enjoy the practice, the path, the moment.
Having written this down I got remembered that all these learning methods, all these exercises might finally lead to the understanding: Letting go and giving room that all this can happen is so much better than greedily wanting something and to stand in one's own way.
Yoga shall liberate.
Liberate from what?
Finally it liberates from the thought that we can do anything. It's all a happening. Enjoy.