I need help with learning from studies
I used to take a reference image, redline over it with simple shapes, then right next to it do my best to copy the redline
But I stopped doing it because I didn't feel like I was learning anything
What should I do?
I want to learn more about making things volumetric so all my art doesn't look so flat and I also want to learn how to draw from imagination and do better studies. I still get proportions wrong a lot if I don't do the redline

My idea is to redline it, copy it, then draw it from memory but I'm not sure how to make it volumetric