Training your brain to do more
3-Dimensional drawings
Get your brain warmed up to drawing more 3-Dimensional
shapes to get away from flat 2-Dimensional drawing.
Not to say drawing flat is bad it's just to help your brain to
distinguish from the two. I find it helpful to think like a 3D modeller
and imagine that you are drawing with blocks.
I did an A4 page after work for a week.
Drawing objects inside box
Another helpful trick is to
Draw objects inside boxes, this should help you see and
align the object's proportions better.
I found this really helpful :)