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Plan your talk so you know where you are going to be drawing on the lightboard. If you need to erase (much) frequently or add another board, it's probably too long.
Pause before starting, and look at the camera. This gives you a clean cut point to edit out your walk-on.
If people are going to watch several videos, they don't want an intro on each one.
Dark clothing works best so your writing is readable in front of your clothing. Deep blue is really nice. No text on clothing.
Expectations for videos are higher than for classroom lectures, but you needn't strive for perfection. Good enough is good enough.
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