Your presentation will be more memorable is you use more images and less text in your slides.
But whether the images are photographs or charts or diagrams, they need to be high quality. Don’t use clip art, or low resolution stock photos with watermarks on them.
I guess most of the time you have zero budget to acquire media to use in your presentations, so here is my list of resources that are FREE.
Free stock photos
Free icons and vector graphics
Designing graphics, diagrams, etc
Colour palette services
Download these as a PDF and save it for use next time you are creating a slide deck.