MacFly, I knew that you were asking about the dropper loop.
I have not done much of any lake fishing. I can see where the dropper loop would be useful for fishing flies at different heights. The knot would have to be small enough to pass through the smallest guides on your fly rod. I would imagine that they never will pass freely through the guides no matter how small they are.
..since I had used the wrong term I wanted to clarify since when looking on line the loops have different uses but seem to be tied the same way… just trying to keep the confusion down to a minimum…
MacFly 
I have used the Dropper Loop and have put them on a bunch of bug FOAM flies. Works okay, but sometimes it is just easier to go off the bend. Less chance of tangles. I did notice that the dropper loop made the fly ride butt heavy so I llike off the eye better. Get a better float in my opinion.
Now that tag that Scruffy mentioned, when stillwater fishing (because it can tangle) I always use a “Y” connection. I pull off about 6’ to 8’ of regular Flourocarbon (P-Line is my brand). I fold it in half but I make one side longer.
I put a loop in the flouro and attach it straight to my fly line (sinking line for the most part). I attach the Nymph or smaller fly to the shorter and Big fly to the longer so it looks like food being chased.
… what kind of loop/knot do you tie for your “y” connection??
MacFly
The same loop knot I tie for everything else 
a surgeons loop. Except if I am running a single leader, then I tie in the Perfection Loop. The Surgeon’s will kick out to one side where the Perfection hangs straight, but on the “Y” connection, it doesn’t matter.
…thats what I thought but you know me.. I had to ask..
MacFly
Okay so I will ask the question - will be float tubing Saturday at a lake in an area where the water is about 8 to 9’ deep.
A floating line with a nine foot leader and the indicator set at 8’ to 8 1/2’ (but keep in mind to add a couple of feet if wind is blowing and you are moving to allow for the fact that the line isn’t going straight down.
I don’t know how many hooks you can use on one line there, here it is two. I put one right at the end of the leader and a “BB” split shot about 6" up to make the whole thing sink fast. Then I tie about 12" of flouro about three feet up and attach my second fly, so now I have one at approximately 8’ and one at 6’. If you can do three, repeat this and put one at 4’. And twitch it every once in a while. Remember also, when that indicator goes down, pull the line with your stripping hand then slowly lift the rod tip. Timing is everything, so by pulling the line, if the fish spits it, it is still in the zone for another try…and they will try.
This is a great way to find the ZONE for the fish. I would still take your sinking line, but this can help you find out where they are holding and then you can adjust you sinking line countdown or retrieve to get it in the zone.
I know people say the fish move up into the shallows when it gets cold, but I find the opposite. They are lethargic and hold in the deep, besides, trout love cold water [;)]
Thanks Flygoddess for the feedback. BTW the water depth is about 8 - 12’ not 8 - 9". A floating line was also recommended by my fly club which is having an outing there next month. Just wanted to hear what the pro [you] had in mind. Needless to say your suggestion were more thorough. When in doubt check with FG.
…sis I am confused here.. but that is nothing new..lol..
..you say to attach your first fly at the end of the leader.. then attach your second line X feet up from there so that two depths are covered at the same time…
.. do you not want to use tippet??? what I had pictured in my mind was to put tippet on the end and work the flies from there.. meaning add a 3 - 5 foot tippet and attach both flies there..
.. anyway.. I hope my question makes some sense of some sort.. [:)]
MacFly
…also if you are using a foam terrestial as the indicator where would you put that and where would you put the second fly??
MacFly (your friendly confused person.. [sly])
MacFly
Macfly, if you use a terrestrial for the indicator, you will have to play with length of tippet to the dropper. I’d start off with that 6’ and maybe shorten as needed.
We are begining to think alike.
I take a 7 1/2’ leader (my favorite length) then I take 5’ of flouro (but keep in mind, if the leader is a 4X the flouro I use will be a 4lb because I haven’t found 5lb in regular flouro and tippet is too expensive. Plus remember flouro is strong)
I take that 5’ and use a Triple Surgeons knot to attach it to the leader…BUT I attach it so the tag is 2’ long and the running line is 3’ long. Then I don’t clip the tag, I add a fly.
Does that make sense?
..so off of a 7.5’ leader you attach 5 feet of tippet (flouro) and do a triple surgeons knot??? with the tag end at about 2’ and the running end at about 3 '…
overall with leader that gives you about 10.5 of depth.. with one fly at 10.5 and the other 9.5’???
.. now if that is correct.. lol. do you put the terrestial “indicator” on the shorther length with a drop on the deeper side?? or..
use an indicator just at the connection between the fly line and leader and then run two flies off the flouro “Y” you created??
MacFly
if this doesnt work Im gonna start dropping m-80 in the water and see what floats up.. [crazy]
Not with a dry. With a dry I would tie the dropper (6’ flouro) right off the eye or off the bend of the dry which will be tied to the end of your leader.
And I need to correct the measurments on the 5’. I would tie it so the tag is 1’ and the running is 4’, then there is a 3’ difference, but you can put the indicator anywhere. So with the 7 1/2’ + the 4’ I am at 11 1/2’ and I would put the indicator at 9’ to start so 2 1/2’ down from the connection of leader to line. This is good like I said if it is windy, cause you can set the indicator for 10 or even 11 feet.
…thank you sis.. that last part cleared it up for me… just as an fyi.. I usually use a popper or foam terrestial tied to a short length of tippet (like a 2x or 3x for larger flies@ 2 - 3 ft) from the leader. and then off that hook I use a perfection loop to tie a second length of tippet (4 or 5 x since the dropper is smaller normally 3 ft or a little bit more)…
if I am not using a popper I will do basically the same thing with two different size flies.. like a # 8 wooly.. and off that a 10 or 12 pt nymph.. copper john etc..
… what I am thinking is include the indicator just below the just after the line/leader connection.. then work with the flies and tippet..
.. I hope that is right.. lol..
MacFly