From imagination :
Hello Amurphyr, I see you're good at drawing faces and seems to be trying to improve anatomy and more dynamic poses such as cross-legged sitting, and I acknowledge it might be quite difficult to get the fluidity of her body to go along with the proportions.
So here what I suggest you: Try to look for reference images, like someone that's sitting in the position in real life, photos, or even art from people that do it really well! Then try to copy it in your own way considering the gravity, how each part of the body interacts with each other and specially body proportions. Copying and using things as reference isn't bad when you're trying to learn(except plagiarism, of course), it is good so that you understand how to draw real things in your own style.
Something I believe to be very important for your improvement, is studying the proportions, for an example, how large should the shoulders be compared to the size of her head, how big or small can the neck be so it supports the head... Things like this are very important to consider if you want to put your ideas into paper better.
Thank you :)
I think you did a good job at drawing from imagination with this sketch of the woman in a cross legged position. A great way to improve on this is going to definitely be some more reference studies and drawing what you see. This way, having done so many times, you will be able to better accurately "draw from imagination".
Your brain is like a hoarder of information. If you draw enough people in sitting or crossed positions like in your sketch, you will be basically depositing mental references in your head. This allows you to pull from them and be able to basically jigsaw pieces together and create even more fun poses that can really show off your skills!