The people in the audience are the stars of your show. If they don't buy what you're saying, it won't go anywhere. To keep them engaged and make your case, you'll need to focus on what matters to them. If you don't, they'll have to work hard to figure out why they should care about your presentation and what it'll help them accomplish, and they'll resent you for the extra effort they've had to put in.
Spell out the big idea: Your primary filter should be what I call your big idea: the one key message you must communicate. Everything in your presentation should support that message. The big idea is what compels the people in the room to change their thinking or behaviour — and that's the whole reason you're presenting to them in the first place. It's shaped by your point of view and what's at stake (that is, why the audience should embrace your perspective). A generalization like "Q4 financials" doesn't cut it. If you don't have anything of substance to say about the financials, why present? Better to send around a spreadsheet and be done with it.
Try expressing your big idea in a complete sentence to make sure it's fully baked. The subject will often be some version of "you," to highlight the audience's role, and the verb will convey action. Be specific. When asked, "What's your presentation about?" you wouldn't say, "Software updates." That's a topic, not a big idea. But you might say, "It's about why production will keep missing key deadlines unless we upgrade our workflow management software."
Once you've spelled out your big idea, generate lots of supporting material to give yourself more to choose from when it's time to pick your best stuff. Go for quantity — designers call this part of the brainstorming process divergent thinking. But then turn your attention to convergent thinking, the filtering and sorting that helps you find material that will rally your audience behind your big idea.
By the way, you don't have to start from scratch when generating content: Dig up other presentations, industry studies, news articles, reports, surveys — anything that's relevant to your big idea. Push on the concepts. Challenge them, or consider them from a new angle, or draw new connections. Then brainstorm new content using stickies (they're easy to move and arrange), whiteboards, mind maps, and other tools. At this stage, more is more, because you may work your way through five, ten, or even twenty ideas until you find ones that are distinctive and memorable.
Wield a sharp hatchet: Once you've gathered lots of material, start cutting mercilessly on your audience's behalf. Say you're presenting a business case for developing a new product, and you've created a mind map in the brainstorming phase to explore issues that could affect the product's success:
Since your priority is to persuade decision makers at your organization to invest in your idea, you'll want to talk about what they'll be interested in: its profit and revenue potential, for example, and how you envision managing market and technological risks. But you probably don't need to get into trends such as agility and serendipity. Though they're important principles in the world of product development, they'd be a distraction in this particular talk. Save them for another presentation.