Everyone has something in drawing that acts as a nemesis. Some people hate to draw eyes, lips, or hands; some people struggle to fully render a drawing.
I find that one of my biggest challenges is being left-handed, and not for the reason you think. Sure, dragging my hands through my work is always a risk, but it’s really defeated by working right to left.
No, my challenge is that I’ve always tilted my head to write or draw, because we live in a right-handed world. I curl my wrist funny (from all those years fighting with binder rings and, of course, not wanting to drag my hand through my work), and I tilt my head.
Why is this a challenge, you ask? Try writing or drawing on unlined paper with your head tilted. Let me know how it goes.