Along similar lines: I often write an e-mail with all of the information I want to include, and read it over and edit it several times to cut down on things that aren't necessary. The unnecessary things can be as simple as an awkward prepositional phrase, but often they are a technicality that is hogging too much space in the e-mail.

I personally think this really improves my communication. In a workplace where people are expected to read through dozens of emails each day, it makes a difference in the information that's finally conveyed to my colleagues, which is often what matters the most to me.