Slides are not the talk
A common mistake is to treat the slides as the whole presentation, and the speaker as someone who reads them out. Audiences handle this badly. When the same words appear on screen and in the speaker’s voice, people read ahead, stop listening, and then wait for the speaker to catch up. When the slides are crowded, the audience divides its attention between reading and listening and often does neither well.
A more helpful view is that slides support a speaker. The speaker carries the explanation, the nuance and the human connection. The slides give the audience something to look at that makes the message clearer: a key phrase, a diagram, a photograph, a number. If the slides alone would make a complete document, they are probably doing the speaker’s job, and may be better delivered as a handout.
One idea per slide
A useful rule of thumb is one main idea per slide. When a point is complicated, split it into a short sequence of simple slides rather than one dense one. The audience can then follow the progression, and the speaker controls the pace.
This approach follows the same logic as any layout: a clear focal point and a plain visual hierarchy. Decide what the audience should notice first, make that element the largest or most contrasted, and let everything else support it. If everything on the slide is the same size and weight, the viewer does not know where to begin.
Keep text short
Text on slides works best as a prompt rather than a script. A few practical points:
- Use short phrases, not full paragraphs.
- Limit bullet lists. Long lists invite the audience to read ahead. A few items, or one item at a time, often work better.
- Make text large enough to read from the back of the room. If you are unsure, test from a distance on the screen you will use. Room sizes and screens differ, so there is no single correct point size.
- Avoid placing long quotations or full sentences in small type.
- If you need to give detailed information, put it in a separate document for people to read afterward.
Good line spacing and a sensible type scale still matter. Clear differences between a title and supporting text help the audience see structure immediately.
Readability: contrast and type
Slides are viewed at a distance, sometimes in bright rooms and sometimes on weak projectors. Strong color contrast between text and background is essential. High-contrast pairings, such as dark text on a light background or light text on a dark one, tend to be safer than subtle combinations. Avoid placing text over busy photographs unless there is a plain or darkened area behind it.
Choose clean, legible type styles and use only a few of them. Display type with a lot of personality can work for a title, but body text should be plain. Following standard accessible design practice, including healthy contrast ratios and not using color alone to convey meaning, helps people with low vision or color blindness and also helps anyone in a poorly lit room.
Use visuals that carry meaning
Images, diagrams and charts are often the best use of a slide because they show what words are slow to describe. Some guidance:
- Choose images that support the message and avoid decorative filler. A relevant photograph usually works better than a generic one.
- Make sure images are sharp enough for the screen. A blurry picture projected large looks worse than it did on a laptop. Check image resolution before you present.
- For charts, apply the ideas of data visualization: show one point per chart, label directly where possible, remove clutter, and make the takeaway clear. Do not let a chart mislead through truncated axes or selective framing.
- Use simple icons consistently, in a single style, so they read as part of one family.
Keep the design consistent
An audience relaxes when the slides behave predictably. Use the same background, type styles, margins and color palette across the deck, with changes only where they serve a purpose, such as marking a new section. Slide masters or layout templates make this easier, and good page templates prevent each slide from drifting into its own style. This is the principle of design consistency, and it saves effort when you edit.
Align elements to a grid so titles, images and text sit in the same positions from slide to slide. Alignment and proximity do much of the quiet work of making a slide look orderly: related items grouped together, unrelated items separated by space. Generous white space helps focus too, and a minimalist design approach often suits slides well.
Be careful with effects
Animations, transitions and sound effects can help when they reveal information in a useful order, such as showing steps one at a time. They can also distract. If an effect does not help the audience understand, it is probably better left out. Keep any motion subtle and consistent.
Plan for the setting
Think about where the presentation will happen. In a large room, text must be bigger and the design simpler. In a video call, slides share the screen with a face and shared-screen compression, so very fine detail may be lost. If the deck will be circulated later, you may want a slightly more detailed version, separate from the one shown live.
Also have a fallback. Check that the file displays correctly on the equipment you will use, that images and type have not shifted, and that you can present if the technology misbehaves.
A quick review
Look through the deck and ask of each slide:
- What is the one idea here?
- Could I remove words and still be understood?
- Can the text be read from a distance?
- Does the visual add meaning, or just fill space?
- Does it look like it belongs with the other slides?
A well-designed deck does not guarantee a good talk, which depends on preparation and delivery as well. But slides that are simple, legible and consistent leave the audience free to listen to the person speaking.