I like this guy's blog 10/20/30 and what he has to say about PowerPoint presentations.
I've sat through soooo many death-by-powerpoint presentations over the years, yet still get given 30 million pieces of information on a regular basis and am then asked to 'create a deck'.
Frankly, that totally knackers the concept of a good presentation. So, I go back to the speaker and work out with them what they want to get across and what they want those on the receiving end to know/feel/do as a result of listening to them.
Normally I'll then draft a script and give it to them to make their own. Experience has proven to me that it's much better for the speaker to have something to deconstruct and reconstruct than be faced with a blank piece of paper.
Once I've got their revised draft back and have made any necessary tweaks to the language and flow to ensure the audience will 'get it', I'll look at where imagery and emphasis will add to what the speaker has to say. Whatever slides - and there won't be many - that go in will amplify their points and add to the audience's understanding.
Then we'll rehearse - preferably with some of their peers as a live test audience - until they're comfortable with what they're saying and how they plan to say it, and look at the presentation in the context of what's around it (is it part of a larger conference session for instance).
Little details like how they'll be introduced, walk-ups and walk-offs, and what they plan to wear, plus the more important aspects such as how and when to handle questions and comments all play a part in the relationship. All in all, the aim's to reach a planned outcome.
In great presentations content management is king - and PowerPoint can be a weapon of inordinate distraction, delivering not clarity but regicide.