Now TZ asked me to write about fishing multiple flies, something that I grew up fishing on the reservoirs. Allow me to divide this into three headings, teams of flies, leader construction and casting.
Teams of Flies (Top, middle, point).
Deer Hair Sedge, Shipman's, Suspender Buzzer.
Mini-muddler, Soldier Palmer, Black Spider
Muddler, Cover PT, Damsel Nymph/Black lure
Olive Buzzer, Black Buzzer, mini-Tadpole/Damsel
(NZ Backcountry) RFU, Tungsten Nymph, small Trailing Nymph.
All these example flies can be found on Sexyloops. If you are unsure of where then ask on the Board and I can find them for you!
The first important thing in any leader construction is to put a butt section in place. So often I see anglers come to flycasting courses without a butt section, this creates hinging as the loop unrolls at the leader join. For floating line leaders I normally always use a RIO trout leader to 10lbs point, then tie in a Sheepgirl ring and add tippet from here. With sinking lines this butt section can/should be shorter.
For dropper knots I use the three-turn Surgeon loop and the downward dropper. The droppers should be around 4inches long. Occasionally you might want to tie off the bend, for example the trailing nymph. If the fly doesn't hang straight then it's often worth retying.
For construction I normally have 9ft leader, 2ft to top dropper, 4ft to middle, 7ft to point (approximately). The important part in this is that the point to middle is at least 1.5 times the distance from middle to bob. Otherwise it tangles.
With the Backcountry setup I go, 9ft tapered leader, 2ft to top dropper, 6ft to nymph, 18inches to trailer (some superglue can help keep the knot in place high up the bend of the hook).
Since you don't want to spend your time undoing tangles, use more open loops both back and forward, and (very important) check the shoot to ensure turnover. Flies should be either weighted at the point, or tapered in such a way that they unroll nicely, the generally means big air resistant ones at the top, slim ones at the point.
Have a great week!