I am thinking of trying to rig two fairly large flies (both weighted size 4) in a tandem rig for river smallmouth. I am thinking of using a variation of option 2 listed here http://theflyfishingbasics.com/two-fly-setup/
I would have 3x fluro attached to my leader and attached to a small ring, I would then attach a couple of feet of 3x and attach to the heaviest of the 2 flies, and attach 8 to 10 inches of fluro 4x to the ring and attach the lighter of the two flies. I am thinking of a craw pattern and a Shenks Minnow, and having a lighter tippet for the shorter attachment might help tangles.
Fish two streamers on a very similar rig (I use a dropper loop instead of a ring) often. However, I’m usually using a shooting head and unweighted flies. I suspect you’ll find that you’ll want to use a heavy stiff tippet material for the dropper to minimize tangling. Rig will be higher maintenance than a single fly rig, and a bit more than a traditional two-fly stem (i.e. off the bend), but it does work.
I usually use a two fly setup in the surf here. A size 2 clouser with dumbell eyes about 3" long with a size 6 surf worm pattern with bead chain eyes. I have had good luck using a size 10 three way swivel. One eye of the swivel attaches to my furled leader. One eye attaches to 3" to 4" of 0X flouro and the Clouser. The last eye attaches to about 12" to 16" of 6 lb flouro and the surf worm fly. You get some tangles but it is manageable.
I fish 2 streamers in the salt most of the time.
Using a loop2loop connection between the leader and tippet, I tie a surgeon’s loop about 1/3 of the way back into my tippet section and attach it to the leader with the loop2loop handshake.
Point fly on the longer leg, dropper on the short.
So simple that there’s no regrets if you need to chop it off
… and sometimes you need to
With this rig, I’ve gotten doubles 6 time in a row with small fish, but two 15lb fish at once was more than I care to handle again
That two fly rig is a good rig. I would add put the heavier/ bigger fly as the point fly. I fish this rig with up to 5 flies sometimes when I am trying to figure out what the fish are eating. Just make sure you check the local rule book to see how many hooks/flies are legal in your area.
Just keep your loops a little more on the open side and let your line completely unfurl in between casts to keep fouling at a minimum.