1. Draw through the object. Draw the space from front to back. Try drawing directly over objects to show 3D space.
2. Line variation - work on sequential line technique. Show variation in one object as well as variation from foreground to background. Avoid variation at same integrals.
3. Don't be afraid of conte! I want to see those heavier lines
4. Avoid using lines as texture (like short marks). By doing this, you are avoiding how to use line variation.