Screencasting best practices

I'm not going to claim I have anything like the gospel in terms of screencasting best practices, since I'm still trying to figure it out myself. I've only used Jing, which is not always reliable (you get what you pay for?), so I would first say, know your software and its quirks. Comparing more than one screencasting application might not be a bad thing.

Know what you're going to say ahead of time. You don't need to have a script, but do know what you need to convey, so that if you're talking without a script you can still get your message across without a lot of dithering. Beyond this, have an idea of the ideal flow for your screencast in your head. Know how what you're saying in the moment fits not only into that moment but into the larger picture.

Know your window sizes for recording and don't move your mouse around too much or too fast.

Be relaxed and don't get stage fright. You don't have to be perfect, a conversational tone is enough. Your voice is probably also enough. You may not like how it sounds but as far as everyone around you is concerned, that's how you sound, so get used to it.