I agree (with the sibling comment) that this is more general advice than just for academic settings.

I can't tell you how many presentations I sit through (or emails I read) that read like murder mysteries. Tell me the conclusion or essential element up front, so that I can frame my consumption a little better. Don't start with the Big Bang, the creation of matter, the coalescing into galaxies and planets, etc, etc and then build up the conclusion from all those constituent elements.