Sometimes it is not possible to create that perfect presentation. For example, your boss landed a pile of slides (written by someone else) on your desk, to be sent out in the next 3 hours after some "fixes".
The presentation below provides some tools for dammage control. Especially useful for PowerPoint files that are intended for offline reading, rather than TED-style ballroom presentations.
  • Use consistent colors. Even is the color scheme is not pretty, even is the color scheme is the standard PowerPoint one, recolor all objects with the same 2-3 colors, throughout the file
  • Align and distribute, wherever you can. Make boxes the same size
  • Wrap bullet points correctly (there are for sure too many bullet points in these type of last minute documents but not time to fix that now), cut words if you can 
  • Un-stretch photos, select format/reset to regain the original image and re-size them by dragging the corners to keep the proportions intact
  • Put all the titles in the same place using guides to prevent jumping titles. In the good old days, I used to hold a prinout of a document against the light to see whether everything is lined up
  • Stay inside your guides so that all charts look aligned.
Good luck. By the way, you can find the "For Dummies" book cover generator here. The "For Dummies" series contains a lot of books related to presentation design and communications. Here is the full liston Amazon, here is one: