One technique is, assume the my listeners know nothing. I try to start from a 10,000 mile high perspective and then methodically zoom down to the details. Along the way, I try to give succinct definitions of every term I use. So even if most students can be expected to know those things already, maybe one or two won't. And if I do a good job of the definitions (and they are kept short), they also help students to think about that thing perhaps a little differently.
In an hour class, it might take me 20-25 minutes to get down to the details. Then I might spend 10 minutes on something "hairy", then back up a bit to something easier, then delve down once more right at the end.
It's particularly helpful if I can find a "stinger" to deliver at the end: something that students might not have been able to realize before, had they not just worked through the problem from the perspective that I've given. Or maybe even something provocative (though I'd try to acknowledge if anything is controversial). Ending well is very important to help students remain interested for the next class, and to help them feel motivated between classes.
I also try to build in some surprises along the way, and change the pace from time to time. Otherwise, everyone might fall asleep.
And, I try to avoid teaching a topic unless I really care about it. It's just too much work to teach well, otherwise.
