Brad,
I consider them right up front. While this web site discusses endlessly the merits of other design features, such as bunker placement, I seriously doubt that there is a web site arguing whether people take the easiest circulation route - i.e. a straight line - anywhere.
That tendency is so strong that you must consider it very early in design, and you must then arrange at least some hazards around it, i.e .putting them predominantly on the other side of the fairway or green unless you accommodate expected traffic. W/o this type of thought, you get worn spots.
Having said that, I was surprised to see Graves and Cornish in "Golf Course Design" (their old book, not the new classic golf holes one) recommend placing cart paths on the inside of doglegs for the reason listed above. I try to put them to the outside, since the eye is also naturally drawn to the inside of the dogleg, and they become very visible.
I also like to keep paths 20-25 yards from the edge of the fairway, but sometimes space precludes that.