Keep your slides simple. Remember that you are delivering a live performance - slides focus attention, but the information is coming from you.
These are two slides that convey the same point: scholarly journal costs are going up too quickly. The first is informative, but cluttered and you lose the point easily. The first slide's image has too many dots, hashmarks, and small type for a good slide. The second is more focused and hopefully impossible to misunderstand. I use notes to give context & explain both, but note the extended text in the second.
Also I decided not to put my sources on the second slide, but may still do so. If anyone asks, I have the reference right there in the notes and would also have it on a references slide at the end of the presentation.