David Maslanka, senior lecturer of applied mathematics at Illinois Tech, created an at-home whiteboard so he could write equations and explain the process, just as he did in the classroom. He purchased an inexpensive webcam and a suspension arm that clamps onto his desk. Maslanka moved several lamps to his desk to highlight the paper, and advises that two lamps is perfect.
For more inspiration, here's how other educators created their own DIY whiteboards and document cameras.