Abernathy was primarily focused on the graphic design of applications. He suggested that many developers hire a graphic designer to do this job, as programmers aren't necessarily good designers. Pixie, a UI "explorer" that is included in the Apple Developer Tools, was noted as a simple and useful assistant for seeing the closeup details of how other developers have achieved a certain effect.
Keeping a scrapbook of good designs is another hint that Abernathy brought up. He wasn't advocating stealing user interface elements -- something that several developers I talked with at lunch have had to put up with during the last few weeks -- but instead to use those elements as an inspiration for future designs. Abernathy suggested visiting Flyosity.com and 365psd.com for excellent hints on how to use graphic tools like Photoshop in designing user interfaces.