Screencasting-what makes a good one?

Screencasting is an extremely useful tool, and easily done with user friendly software. After several tries at it, I realize there are techniques and rules that apply that make screencasting effective:

• Have a topic or idea and a plan prepared ahead of time.
  
• Practice - the first cast is usually not the best.
• Keep track of trials by labeling them accurately.
• Play with the sound settings on the microphone and speakers to get optimal results.
  
• Play back the screencast - seeing it and hearing it before posting allows for editing.
• Be aware of the length - too long or too short is not ideal.
• Know who will be watching the screencast.
• Avoid speaking monotone - use enthusiasm in line with the presentation.