I think the phrase "Make it Bigger" is probably one of my favorites. I saw Paula Scher speak in Boston, and her talk centered on that idea. For designers, it's a phrase that often comes across from the client's side of the table...as in, make our logo bigger, so there is a double entendre since much of Scher's work is about scale and changing what we're capable of visually accepting...always a thought I liked a lot.
I came across the book again about a week ago and looked through it. At the end, I found the excerpt up here. I have paraphrased so that it's a bit more generalized but this is the essence. Push it! Then push it again!