The fishing guide industry has rapidly evolved toward "red plastic bobbers " as the most reliable way to generate tips at the end of the day, particularly from inexperienced or beginning fly fishermen. I'm not going make judgements. I worked that way for many years too and I understand making a living comes first. I even fish that way myself at times. But not all that often and it is my least favorite way of doing things.
But that's not to say I don't use bobbers. I just don't much like the big round red plastic ones. I do a lot of fishing on big fast moving rivers like the Yellowstone and Upper Madison with foam grasshoppers atop a beadhead or even a small streamer. Some of my foam grasshoppers are so big I can float them over top a large and heavily weighted streamer. Foam grasshoppers, however, are not so well suited to smoother tail water fisheries or spring creeks. I worked over a large pod of dimpling rainbows on an un-named tail water a few weeks ago.
The river was a bit silty and off color. During the government shutdown. The campgrounds were all closed and the river was almost empty. There was a steady breeze and the lighting was tough--overcast and constantly changing with fast moving clouds. And I'm 65 now with s*&$$y eyesight. I need a bobber of some kind in those conditions or I can't even fish. But foam grasshoppers didn't work well that day. I didn't actually put any fish down. But I made the pod move 30 feet away every time I put a cast down. I switched to a big #10 Humpy as the bobber with a #18 soft hackle wet fly trailing behind and had much better luck. Others I know like to use the Royal Wulff that way, as a bobber during Blue Winged Olive time.
Perhaps even better yet, the best bobber I've been able to find is one of my first inventions: the Werewolf. A fly I started tying several thousand years ago when I was a teenager. The Werewolf floats like a cork and it's easy to see because it has a white head made from white antelope hair. And yet it lands lightly without making a fish-spooking plop. Not many non-foam flies float better than a Werewolf. Easy to see makes it hard to beat. The Royal Wulff works well in that regard too. But it doesn't float quite as reliably as the Werewolf. And the Royal Wulff is too fussy and time-consuming to tie. For me anyway. I used to think of the Werewolf as a high altitude cutthroat fly. Now I think of it as my number one smooth water bobber. That also catches fish.