These videos show you how to sketch simple shapes in two-point perspective. I use a Wacom Intuos graphics tablet with Autodesk Sketchbook, but you can also follow them all using conventional, paper-based sketching techniques.
Start with the introduction video shown right. This will explain the differences between 3 Point and 2 Point perspective.
The two videos shown below show you how to create ellipses in 3D to a bit more depth than those shown the in 2 Point Perspective tutorials.
Like with the two point perspective tutorials, the videos below show you how to transfer the theory (above) into practice of product design sketching.
You can print out the worksheets below and copy the shapes shown if you don't have access to a tablet.
This exercise will show you how to create a chair using basic block shapes in 3 Point Perspective