Join Date: Sep 2012
Location: Central Western NSW, Australia
You're doing quite well.
References are the key, and they go hand in hand with practice. If I were you, I'd gather up a collection of high-resolution photographs with good shadows and highlights and draw draw draw. Don't spend too much time on them, give yourself maybe 10 minutes on each. Also, make sure you cover lots of angles. My mistake is that when I draw, I always draw profile, so my pictures always lack the realistic, 3D feeling.
There are much better artists on here than me though, so I'll hand you over to them xD
Your teacher really doesn't sound helpful. You need my teacher, he made us do everything ourselves and would guide us the whole way through.