Here's another trusty tip from my speech coach: Rehearse your essentials.
I'm frequently booked to give a short talk about a long subject. It can be nerve wracking, trying to figure our which points I'll cover and which ones I'll cut. For years, I'd focus on developing an outline, then cutting out the fat until I had a talk that fit the time constraints.
A few years ago, prepping for a big talk, I asked my coach (Nick Morgan) what he advised in this situation. He said, "don't focus on what you'll say, focus on what you cannot afford NOT to say."
If you think about it, he's right. You will hardly ever give a talk, then later think, "I wish I wouldn't have included that slide or told that story." Instead, when you feel like you were time crunched, you think, "I wish I would have remembered to tell that story or show that slide."
What are the points that you absolutely MUST make?
1. One data point that ties your presentation to the audience or context.
2. The key action items.
3. The key story that will help people move from listening to believing.
Don't try to identify more than 3 "must make" points and don't assume they are the same for every single talk. Try this next time you give a talk, and you'll thank yourself later.