My favorite subsurface leader with a floating fly line is H&H braided butt fluoro leader - I buy both 4x and 5x, but with 4x usually you need to add 5x fluoro tippet to tie on this hook. These are knotted leaders with a braided butt.
http://store.hookhack.com/Braided-Butt- ... o/HHBFT94/
I'll slide my size 14 wet fly attractor up the 4x, and add 18" of 5x tippet to tie on the BWO dropper, letting the leader-to-tippet surgeon's knot bump-stop the attractor fly.
Altogether, I fish about 6' of fluoro leader/dropper beneath the braided butt. With 3x and 5x tippet, you can rebuild these leaders as needed, even at streamside.
I smear the braided butt with Mucilin - this is Very Important to help keep water out (drag the butt through the tin with thumb over it a few times, then rub it in). Fishing a wet fly attractor with the BWO dropper, it's all the strike indicator I need. It also keeps the fly line tip from swamping. When the braided butt begins to swamp, I use a chamois to wring it out, just squeeze and slide it through the chamois. I carry my Mucilin in case I need more, but usually just wringing with the chamois is enough.
I tie a caddis soft hackle wet fly with an XS black tungsten cone head, or a sparkle nymph tied the same way (size 14 sproat), and that is all the weight I need - sorry, no photos of the fly. But the attractor is also my weight, eliminating the need for split shot, and makes the whole rig swing more naturally. The tungsten cone head attractors catch fish, too.
(A REALLY good hook for the wet fly is Kamsan B981 No 10 - Swedes have their hook sizes all messed up; Partridge makes a good size 14 sproat)
You can still add a strike indicator if you need to fish shallower, but it seems the most effective wet fly swings, especially in deeper water, is using the braided butt leader without an added indicator.
Nice about a Thingamabobber strike indicator is that you can add it and remove it anywhere on your leader.
I loop-to-loop everything, and if I go to dries, which we do have on the Guadalupe, I swap the whole leader for tapered monofilament nylon.
Typical BWO spot, there's a riffle and chute above this run.
Getting downriver to this spot, there is a long wide shallow flagstone run that is often good sight-fishing. This same rig is perfect for down-and-across casts presenting to visible shallow fish.
I can think of one deep gravel bar slope and tail-out where I rig first with a Teeny BS-100 (5-wt or less) or T-130 (6-wt) sinking line to swing wet flies. I fish these lines with 4' Teeny tapered leaders (zap-spliced) and 18" tippet.
The same rig works well moving downriver from here - and of course you may end up stripping the sinking line to keep it off the bottom - bottom bouncing can be a really good tactic.
You don't do a whole lot of tight-line drifting before your swing with this set-up - you just make down-and-across casts and let it swing.
Here I use an unweighted wet fly attractor and the BWO dropper.
This is really good caddis water, and there's a hatch every afternoon on the gravel-bar tailout you can see under the bend in my rod.
you can see my soft-hackle in her mouth
As with most wet-fly swings, there's not much question when you get a strike, and this rig is entirely by feel.
Making a swing - generally you drop the rod as the rig is drifting past you, then slowly lift the rod when the current is dragging and your fly is in the target zone, causing it to rise like a swimming caddis or BWO. And it's just about as fun as fishing can get.
Up to now, what I've mostly been talking about is fishing the drop below a riffle/chute.
You mentioned fishing riffles. For riffles, I tie a Unibobber parachute dry for a strike indicator, and add a BWO dropper, and will split fish between the dry/bobber and dropper.
I'm pretty sure this November fish is a wild-spawned Guadalupe male with my BWO in his mouth, and caught a half-dozen siblings that day (split between the top and bottom)
This probably isn't a TIC fish, since the TIC trout are all females.
This rig is for tight-line nymphing, usually the slower water, but the fish below is from a deep, fast chute.
I fish Otter's milking eggs with a thread midge dropper. I learned this from Frank Smethurst, who said when you absolutely positively need to catch a fish right now.
I use a quilting needle to put the egg up the end of the leader, slide up a bare size 12 sproat hook (a 1x-long wide-gap hook), tie on 18" tippet to bump-stop the bare hook and egg, and add the midge. I always fish this with split shot and an indicator. When I add split shot, I put a square-knot loop in the leader, close the split shot on the loop, and tighten the square-knot. It stays put and I can stack more split shot above if needed.
Here's a trout that took the egg - the fish is on the bare hook and the egg has slid up to the split shot
You can see the size 22 thread midge dropper at the bottom center of the photo
When I'm done with this rig at the end of the day, I'll clip above the split shot and add a surgeons loop, wrap the whole rig up in a leader wallet, and add it loop-to-loop to my leader next time.
size 22 thread midges
Earlier the same day, this buck took the size 22 midge
and if you want to see more of him, we're gonna need a bigger net