One thing that really helps me (and speeds play) when I'm on a course for the first time is yardage markers that are visible from the tee. Sometimes due to the topography yardage estimation from the tee can be difficult. I know a lot of people hate the little poles at 100/150/200 yards (especially if they are in the fairway) but they come in really handy for me off the tee.
When I hit a drive (or even a half wedge, for that matter) I can see the ball just fine to its apex and beginning its fall, but I've always had a lot of problems tracking falling objects, so I'll lose it on the way down. Like I said, it happens for all shots, even a 50 yard lob, so its not a matter of poor visual acuity, just something my brain doesn't do well for whatever reason. So when I hit a drive, I watch the ball until it begins to drop, then follow where I think its falling and expecting to see it land.
If I hit a ball that might carry around 280 yards, but since I don't know the hole I'm looking 230 yards out or 330 yards out I won't see it. By the time I get there and can find sprinkler heads I can at least have a better idea where I should be looking, but I still lose some balls that way and waste time finding those I do locate, where if I was able to see it land there would be no delay at all.
They are also useful for me to know where to aim on a dogleg. If I think the fairway starts to bend much further away than it does I might play it straight and fly well through the dogleg, or I could attempt to bite off too much and fall short if it is much further than I think. Strokesavers are usually good for this issue, but only if they are available.