drawing starts at ground zero. Ground zero is a point in space. If you can draw a x,y and z axis with 90 degree angles, you can draw any form, in any position in space.
Parallel lines converge. All parallel that movie away from the picture plan must converge to a point on the horizon line.
Structural Geometry is at the core of design and the structural foundation of all things. If you can draw it, you can map it, if you can map it, you can built it.
Mastering the cube. The cube is the most important form to learn. Exercise 1 and 2, draw as many cubes floating in space as you can with 2 hours, Focus on variety of size and position. When you have drawn them all.
Joining and connecting the primary forms. Experiment and play at joining different forms together, to create unique structures.
Drawing basic forms
Learn to draw with structural geometry. If you start with a point in space and draw an x,y and z axis intersecting at 90 degree angle you can draw any form imaginable. When you can draw it, you can map it and when you can map it, you can build it.