Don't do a video to sell something. I am not that convinced they work for that. Do it because you like multiple ways to communicate. Do it because it's fun-- if it's not, don't do it. For me, creating a video is interesting-- even when it does not work so well. Sometimes it just doesn't fly, and I leave it to come back another day. It does require being in the right or should that be 'write' mood.
For reasons of sound control, I mostly have used the webcam above my computer. I keep thinking I'll do one outside with a camera but so far have not. My preparation is pretty much to look at what is behind me. I prefer it to not be cluttered, pillows where they belong, etc. For this one I already had the maps up for the fifth Arizona historical; so they weren't going down. I don't write a script or create an outline, which means sometimes I blow it. I don't write anything down because I want it to feel like a conversation, not a lecture. Ideally it should feel as if you and I were sitting across a table from each other, and I was telling you about something of interest to me. Of course, you don't get a word in-- until it's over anyway.
I generally have music on for background. I've noticed that with it, the log truck that might pass by, is not noticed. It appears to modulate sound.
For awhile I did more of these, because as much as I love books, I am a visual person who loves talking-- yes, introverts can love talking ;). It though has been quite awhile since I created one (October when I looked).
The topic for this one is Rose's Gift, my first eBook about a senior citizen-- some say elder... others the elderly. Rose is sixty; so you decide. I liked writing a story about a woman who wasn't young and yet-- she wasn't done either. I could say more here but why not watch the video.
Incidentally, if you have a slow system, one way to watch these is hit the arrow to start; then put it on pause for a minute or so, while you go off to get a cup of coffee or tea and it buffers. My granddaughter taught me that one.