Jon's point about slight doglegs is a good one.
I think Colt also used bunkers and these slight turns to focus the player's attention on the hole he is playing and not to look around at what's adjacent. He was really good at triangulation and used that along with siting of par 3s to make it feel like the holes aren't on top of each other.
His routing at Saint Germain is especially clever. There, the course crosses a railroad bed to play holes 3-6 & 12-16, mostly surrounded by forest. The holes on the clubhouse side of the railroad are much closer together, but intricately routed so one doesn't feel crowded. I just took a look at an aerial view, and greens 3, 7, 10, & 11 fit into an area less than 5 acres, but the green sites are such that there's really no feeling of being crowded.