One of the typography elements I play with all the time is leading, the space between 2 lines of text. PowerPoint sets the leading standard to 1.0, or 100% of the typeface size. What leading looks good depends on:
  1. The typeface you use
  2. All caps, sentence caps or lower case
  3. And most importantly: the size of the font, bigger fonts need less leading
There is no general rule here, you need to fiddle and see what looks best. On a Mac, there is a button that controls the leading of your paragraph, see the screenshot below. It is one of the buttons I use most.

If you liked this post, why not subscribe to daily updates about presentation design via email? Just blog posts, no spam, or you can follow Jan on Twitter to never miss a thing.