Choose a theme that is appealing, but not distracting. (Free Google Slides templates: Slides Carnival, Slides Mania)
Simplify and limit the number of words on each slide. Use key phrases and include only essential information. You will elaborate in the content in your presentation.
Use good quality images, videos or gifs that reinforce and complement your message. Do NOT use images just because they are cute. They need to relate to the information on the slide.
Images on slides should be a consistent format, either all photographs, or gifs or clipart.
Use one font for titles and another for paragraphs.
Make sure ALL fonts are clear and easy to read. Only titles should be bold.
All slides should use a minimum font size of 24 points. Titles should be at least 30 points.
Practice with someone who has never seen your presentation. Ask them for honest feedback about colors, content, and any effects or graphical images you’ve included. Then practice again!