TL;DR:
Decide the one thing the audience should remember before you open the slide app.
One idea per slide, with the idea as the title. Put the detail in speaker notes, not on the slide.
Use a picture, chart or number as the visual on each slide, not more text.
You have two pages of notes from a project and a meeting in the morning. The tempting move is to paste the notes into a slide app and break them across slides. The result is a deck of dense text that people read instead of listening to you. A better route is to decide what you want people to take away, then build the slides backwards from it.
Start from the message, not the notes
Write one sentence: "After this talk, the audience should know or do ___." Everything in the deck must serve that sentence. Read through your notes with a pen and mark each item as needed, useful, or only interesting to me. Keep the first group, trim the second, and drop the third. This is the hardest step and the one that makes the deck short.
Make the outline first, in a plain text document
Write one line per slide, in the form of a claim: "Sign-ups rose after we shortened the form", not "Sign-ups". A title that is a full sentence tells the audience what to think before they see the evidence. If you cannot write the sentence, you have a topic and not a slide yet.
Worked example: an outline into eight slides
Say your notes cover a pilot of a new shared calendar for a ten person team. These are invented details. The outline becomes:
The calendar clash problem cost us missed meetings. Visual: a screenshot of two overlapping bookings.
We tried one shared calendar for four weeks. Visual: a simple timeline with four boxes.
How we measured it. Visual: the two things you counted, such as missed meetings and booking time.
Missed meetings dropped. Visual: a bar chart with two bars, before and after, using your real counts.
Booking took less effort. Visual: one large number, taken from your own tracking.
What people did not like. Visual: two short quotes from the team, with permission.
What we recommend. Visual: three bullets at most.
What we need from you. Visual: one decision and a date.
Check the count: eight lines, eight slides. The first names the problem, slides 2 and 3 explain the test, slides 4 to 6 give results, 7 recommends and 8 asks for the decision. A good flow for a short talk is problem, method, result, ask.
Building the slides
Create one slide per outline line: Paste each claim into the title of its own slide. Choose a plain layout with a title and a blank area, and use the same one for every slide.
Add the visual first: Put the screenshot, chart or number in before any other text. If you do not have one, a simple shape or a single word is better than a paragraph.
Cut text to a few words: Anything you are tempted to type under the visual is a spoken line. Move it.
Write speaker notes: Most slide apps have a notes area under each slide. Put there what you will say, the source of each number, and the one detail someone might ask about.
Run through once aloud: Time yourself. Each slide should take about as long as it takes to say its title and one explanation. Cut slides that you rush past.
Visuals that work
A chart should make one point: label the two bars, and the claim in the title tells the audience which to look at.
A single big number can carry a slide, as long as the unit and the comparison are clear.
Use a real screenshot when you are talking about software, cropped to the part that matters.
Keep colours and fonts to a minimum: one font family, two colours plus black and white.
Make text large enough to read from the back of the room.
Before you present, send the deck to one colleague and ask a single question: what did you take away? If their answer is not your one sentence from the start, change the titles until it is.
When time is short, cut from the middle. Keep the opening problem and the closing ask, and trim the method slides, since the audience cares most about why it matters and what to do next.
Mistakes to avoid
Putting the notes on the slide so the audience reads while you speak.
Eight bullets on a slide because they were in the notes.
A chart with a title like "Results" that does not say what the result is.
Inventing a visual to fill space. A blank section is fine.
Skipping the rehearsal. The first time you say it aloud is when the missing slide shows up.
Doing it faster
Once you have a deck that works, save it as a template with your layout, fonts and a blank notes area. Next time you start with the outline and drop it in. If you want to talk a rough outline through with someone, DuckyHelper is always there on Mac, Windows and Linux: press one key and ask out loud while your slide app stays open.
Frequently asked questions
How many slides should I have?
Enough for your time and no more. A rough guide is about a minute or two per slide, but let the message decide.
Should I hand out the notes?
If people need the details afterwards, share a short document or the speaker notes separately rather than crowding the slides.
Get started
