Make a plan of what you are going to say in the presentation before you start.

Keep the background VERY light, and the writing VERY dark, or the opposite way round. Don't use colours in the middle.

No more than 8 words on a page, or one short sentence.

Keep your font size at least 24point.

Make reference to every source of images in your bibliography.

Use diagrams or pictures or photos to make the points you want.

Talk about the slideshow, don't read from a paper or cards.

Start with an introduction, saying what the presentation is about, and finish with a conclusion.