The section on caring about people's time [0], a.k.a. prefix-competitive docs, is great. Prefix-competitiveness is widely and easily applicable and provides a lot of juice despite how obvious it sounds. It's relevant for docs, slideshows, emails, and communication in general.
(I wish that section came first.. :p)
[0] https://github.com/hackergrrl/art-of-readme#care-about-peopl...