How much content should I plan per slide OR What to do about very crowded slides?
Crowded slides can overwhelm your audience and can put them off. People love simplicity and same applies to your slide content.
How to simplify the crowded slides
Avoid copy & paste of large chunks of data onto slides.
Try to split the complex content into series of slides - This will be less overwhelming for the audience and will have better chances of mental registration.
Derive a key message from the verbose content and state it preferably as a key-word or a one-liner. Get rid of non-relevant content blocks within the slide that may distract your audience.
Finally - Understand that your slides need to communicate VISUALLY. Don't expect your audience to read the slides in a way they read documents.
At Graphic Impressions - that's what we are good at - converting your content to visually rich messaging. We do this by studying the context of slide-wise content and then transforming it to info-graphic for best visual experience.