A presentation has 3 basic elements: the words you say, how say them (tone and body language), and your visuals. In general, these elements should work together to make a good presentation, but they shouldn't repeat each other.
The biggest danger for beginner presenters is reading from visuals. This makes for a bad presentation because you lose your connection with the audience, and they may get bored with both reading and hearing the same thing. In the next section, I will give you some principles to help you think about how to design visuals to help you and please your audience.
I think it is worth mentioning here that while you see me teach using slides every week, this is not a good example of how to make or use visuals. While teaching and presenting are similar in some ways, they are not the same. Very often, my slides (and body language, and words) are terrible examples for you to copy in your presentations, so please don't do that!
The only time you should look at your visuals is when you are pointing something out to the audience. The rest of the time you should be looking at them.
Therefore, you should only put on the slides what you want your audience to see. Your presentation should be well-rehearsed enough that you don't need your slides to keep you on track. (See this page for how to rehearse and speak naturally.)
People are bad at multi-tasking! It is very difficult to comprehend two things at once. If your audience is looking at your visuals, and especially if they are reading your visuals, they won't be able to listen to what you are saying.
To avoid this, you can do a few things. First, keep your slides very simple. Your audience should be able to look at the slide, take in the information in a few seconds, and then focus on you again. If you do need to put lots of information on a slide, give the audience time to process it before speaking again. Second, use animations to present information when the audience needs to see it. Don't put all of the information up in one go, because the audience will try to read it before you are ready to talk about it. Third, try to make use of non-verbal information (images or colours) on your slides because these won't interfere so much with listening to you. Finally, try not to put anything distracting (like GIFs that repeat) on your slides, or people will keep watching them rather than you.
You might think that when people read or listen to something, they see or hear every word, and figure out what it means in that moment. But this is not true! Actually, people try to use their previous knowledge of a topic and then compare it to what is said or written. This is a much easier way to listen to a presentation.
So, in a presentation, you will help your audience to understand much better if you tell them what they can expect, and remind them when it's happening. Try to have a slide that outlines the presentation at the beginning, and then when you transition to a new part of the presentation, let the audience know which part it is. But keep it simple. You could do this with single words, or even images, logos, or colours.
Even in your first language, it's difficult to concentrate on the exact words that someone says, or to hold a lot of large numbers in your head at once. If you important words, such as a quote, or some text you want to analyze, put it on the screen. Similarly, if you want to deliver numerical information, write the numbers on visuals or use a chart. Once you have done this, you can use your voice to explain.
You have read about the theory. Now here are some practical tips for making visuals.
Quality & Consistency: If you are using images, make sure they are high-quality and don't have watermarks. You can often use AI generated images to make your point. Also, make sure that your slides all look similar. You could use a theme or template.
Keep it simple: Don't put too much text, or more than one image, on a slide. Try to avoid writing in full sentences.
Test your visuals: If you can, put your visuals on a screen and go and sit in the audience. Check that the text is big enough, and the images are clear.
Get feedback: It is very difficult to know how an audience will react to your slides, so ask a friend to have a look and tell you what they think. Concentrate on whether they can see clearly and understand your points.