Hi guys.
Currently, I am a beginner in the industry, just landed my first internship job at a pretty good studio. Along the way of my training, I’ve realized that I only know how to use the tools (Maya, zbrush, SP, SD…) but seriously lack basic fundamentals about traditional arts like 2D drawing. I am planning to join a drawing class to fill up what I’m lacking because there is a girl in my team who also a trainee as well. She barely knows how to use software (enough to press the right buttons) but her painting and drawing skills are really good and she renders always have something very pleasing and artistic than everyone else.
So I really appreciate it if some pros here who have worked in the industry for years can tell me. Which things in traditional art (proportion, form, shape…) help you grow your 3D career and make decent looking renders. Which of them I should consider put my time in and improve and what not to. Thanks in advance 
Wish all of you the best.