Most managers believe they know how to present. They do it every week, sometimes every day, so somewhere along the way the skill just becomes assumed. That assumption is exactly what makes these mistakes so hard to spot – and so damaging when they happen in front of the board.
After working with over 100 corporate clients – including NBCUniversal, Samsung, and ING – I keep seeing the same ten mistakes, in different industries, at different levels of seniority. None of them are obvious. But the people sitting on the other side of the table notice every single one.
Mistake #1: The Data Dump
There's a widespread belief in corporate life that more data means more credibility. The more numbers on a slide, the more rigorous the analysis looks. In reality, when a slide has fourteen figures and three tables, the audience stops processing information and starts waiting for it to end.
One key chart or table. One key message per slide. Everything else belongs in the appendix – available on request, not on screen.
Mistake #2: No Clear Ask
The presentation ends. There's a pause. "Any questions?" And nobody in the room knows what they're supposed to do next. Managers spend hours preparing content and almost no time defining the purpose of the meeting. Without a clear request – one specific action, one decision needed – the whole thing dissolves into a discussion that leads nowhere.
The last slide should contain one sentence: what you need from the people in that room. That's it.
Mistake #3: Reading the Slides
The presenter stands with their back to the audience, reading out loud exactly what everyone can already see on the screen. According to the State of Virtual Meetings report, over 84% of participants multitask during virtual meetings – either frequently or occasionally. Reading from slides is one of the fastest ways to guarantee it happens. Slides are there to support the speaker, not replace them.
The slide carries the visual. The presenter carries the meaning.
Mistake #4: Unstructured Narrative
Most presentations don't lack content – they lack a spine. One thread leads to another, a side point gets introduced, someone adds context that felt relevant at the time of writing, and by the end the audience isn't sure what the main argument actually was. This kind of narrative chaos is surprisingly common even among experienced managers, precisely because the presenter knows the subject so well that every detail feels worth including.
The problem is that familiarity with a topic doesn't automatically produce clarity for the person hearing it for the first time. When the structure is loose, the key message gets buried – and a buried message is, for all practical purposes, a message that wasn't delivered.
Mistake #5: Facts Without a Story
Data is necessary. Nobody's arguing against that. But a slide that says "Q3 results show 15% growth" and moves on doesn't give the audience anything to hold onto. Stanford research puts it plainly: people remember facts embedded in a story 22 times better than facts presented in isolation. Without context, the numbers land and then disappear.
Wrap each key data point in a short scenario or case study – something that tells the audience why that number matters, and to whom.
Mistake #6: Slides Designed for the Presenter, Not the Audience
Notes, arrows, dates, logos, reminders – all the things that help the presenter remember what to say. The problem is that none of this helps the person watching make sense of the information. A slide packed with the presenter's internal scaffolding is essentially a slide that asks the audience to do extra work to find the point.
Before building any slide, ask one question: what does the viewer need to understand from this? Start there.
Mistake #7: Wasting the First Thirty Seconds
The presentation opens with a slide listing the agenda, followed by some background on the project, followed by a thank-you for everyone's time. By the time the actual content starts, half the room has mentally left. The first thirty seconds determine whether people will genuinely listen for the next twenty minutes – and most managers treat those seconds as a formality.
Open with the problem or a striking number. The agenda, if it's needed at all, can come after the hook.
Mistake #8: Complexity as a Proxy for Intelligence
The more complicated the slide, the more expert the presenter must be – at least that's the logic. In practice, complexity tends to communicate the opposite. When a manager can't explain something clearly, it usually signals that they haven't fully worked it out yet. Clarity is a competitive advantage, particularly in boardroom settings where decision-makers have limited time and no patience for information noise.
A useful test: if you can't summarise the slide's point in one sentence, the slide probably isn't ready.
Mistake #9: No Visual Hierarchy
Everything is the same size. The same weight. The same colour. The eye scans the slide and finds no entry point, no obvious sequence, no sense of what matters most. Visual hierarchy isn't a design preference – it's the architecture of attention. Without it, every element competes for focus equally, which means nothing gets it.
One dominant element per slide. Everything else supports it.
Mistake #10: Preparing the Deck Instead of the Delivery
Five minutes of rehearsal, four hours on PowerPoint. The result is a beautifully formatted file presented by someone who stumbles through it, loses their place, and reads from the screen. The board isn't looking at the details on the slides – they're looking at the person. And what they see is someone who prepared their document and not their performance.
A rough rule that works: for any important presentation, split your preparation time equally between the deck and the delivery. It feels wrong at first. The results speak for themselves.
So What Now?
Each of these mistakes is fixable in a single training session. The harder part is knowing which ones your managers are actually making — because most of them have no idea. They've been presenting this way for years, getting polite feedback and quiet disengagement, and nobody has told them what's really happening on the other side of the room.
If you want your team to stop making these mistakes, take a look at our presentation skills training here.
Enjoy your presentations!
Piotr Garlej
