Mike,
Love the topic. I have been focusing on designing a course you could play every day for a while now. Not that I believe I usually got too far away from it, but realizing that I probably had. Like most of us, I think we get caught up in the visuals, leading to more bunkers and other drama for photos, awards, etc.
A byproduct of the age we live in, but not hard to figure that if the main design purposes aren't every day playability, then the course isn't as likely to have that when built. Of course, it started well before the 1990's, with the RTJ/Wilson "championship course wars" of the 1950's, at least IHMO.
As to achieving that, I can agree with everything written so far. As for nitty gritty, I would say fewer bunkers, fewer full and partial cross hazards. When I play courses any of those RTJ and Wilson courses of the 50's, I wish there were fewer green side bunkers, and the ones left had been pulled back just a bit one less player per foursome would find themselves in a troubling bunker - speeding play, reducing frustration, etc.