When fishing tandem flies, I keep my leaders on the short side: 6’-9’ in most instances, with long, heavy butt sections. For tippet material (on my leader and between the flies), I use stiff mono (e.g. Maxima) or fluorocarbon in lengths varying from 12-48”. So long as you keep the leader and dropper length reasonable for the size and weight of your flies, good stiff tippet help will prevent wind knots and other tangles. Slow down, open up your loops, and experiment until you find what works by varying your casting style, leader/tippet, and tandem rigs.
In terms of fly selection, I’ll fish different patterns, or at least different colors/sizes until I determine what the fish want—throwing two (or more, for the brave) flies is a great searching tactic. Sometimes, when you hook one fish, another will follow and slam the dropper! The flies mentioned in this article are just a starting point—keep trying different combinations of whatever matches the prevalent local bait.
When fish are visibly feeding up top or in shallow water, I like to throw a popper on a floating line, trailed by a small Clouser or Deceiver-style fly about 2.5-3’ back. If the water is very shallow, I’ll throw a Clouser or Bendback dropper that just ticks the bottom. I incorporate foam and deer hair in these poppers for extra buoyancy. When fishing these rigs blind, most strikes come on the dropper, but every so often there’s that heartstopping blowup on the surface fly.
In the middle of the water column, I’ll ordinarily pitch a pair of Deceivers or Thunder Creek Minnows on a floating or intermediate line. Sometimes two light Clousers will do the trick, but headaches increase with the extra weight. There’s nothing magical about these setups, but for the fact that they sometimes yield this:
Further down in the water column, I like to cast a Clouser, trailed by a semi-bouyant suspending fly like a Thunder Creek Minnow. This is an immensely effective duo when the fish are being selective; the suspending fly irresistibly twitches, floats, and dives.
At the bottom, if using a floating or intermediate line, I throw as modest a Clouser as possible, trailed by a Bendback or other hair fly to search. Using a sink tip and a pair of Deceivers or similar flies is preferable, but I don’t always have another outfit or the inclination to switch lines. I really dislike throwing tandems down in the depths (8’ +), but if you feel like braving the tangles, I at least recommend using an appropriately aggressive sink tip and lighter flies, as opposed to casting ridiculously weighted flies.
Next time you’re out with the long rod, consider throwing on a tandem as a searching rig (popper-dropper being my go-to), or double up on conventional flies when you’re working a confirmed school of fish or established productive structure. Throwing two flies in the salt isn’t something I do frequently, but every so often, the conditions are perfect to increase to odds a bit by doubling up.