Currently I am agonizing over several large presentation files, which I happened to reprint to PDFs...

One thing I wondered: Do PPT's (from Microsoft Powerpoint) always to have to be that big?

And what would be the strategies to make a PPT smaller? (If we say "ceterus paribus" at e.g. 25 slides and assuming that one isn't allowed to use a cloud-based service like GDocs, rocketslide or Prezio.)

Of course there are the obvious "bad guys": Images and graphics.

But: How about roll-over animations etc, who knows how much space they take? How about "smart arts"?

Could one save file size if one would use "Open Office" or "Libre Office" Impress? (I didn't try it yet.)

And "what if": What if we need to include e.g. five images (or charts that can't be remade in Excel in time), how would we best reduce the file size impact of those five images, if we needed to?

I ask all this from an honest "business" perspective. I am no nerd or "Microsoft MVP" and I don't intend on delving into LATeX or similar yet. But that doesn't mean that I am not curious and very willing to learn.

I am basically interested in (proven) best practices.

Yes I know this question is lacking "initial research", but I think the perspective of my question is interesting and unique to a lot of people and if we intend to make SE a "Q&A" / Wiki kind-of reference site, this question might be a good way to "collect" advice on a question that has a very defined goal:

Minimum file-size.