For our purposes in this class, contrary to the original version of this set of training hints by Phil Agre, we'd prefer people did not take notes. When they're writing their attention is focused on what you already talked about, not what you're talking about now . However, you might want give out your handouts after the instruction, so people don't sit there and read them. Don't take over the keyboard. Give people a chance to do things on their own.
People retain much more of what they learn that way.
When they're looking at you, look back at them. If something is true, show them how they can see it's true, and keep it simple. Don't say anything unless you intend them to understand it. Keep adjusting your language downward towards concrete units until you don't see blank stares. Once again, if you're suspicious that they're not getting it, ask them.