Lefty's Deceiver was created by Lefty Kreh in the 1950's and since that time has been a staple in saltwater fly fishing. Although fairly simple to tie, there are a few spots that even seasoned tiers have trouble with.
Here I'm going to tie one on a size 2/0 Mustad 34007 hook. Once you have the hook firmly secured in your vise, load a bobbin with fairly heavy tying thread, here I'm using 140 Denier Ultra Thread in fluorescent yellow.
Although you can start your thread back at the bend of the hook, I prefer to tie in up just a little ways behind the eye and then wrap open spirals back to the bend. When you get to the bend, create a small bump of thread which will help to secure the tail.
There are several ways to put the saddle hackles together to form the tail. I like to use Lefty's method. Just grab 4 or 5 feathers and kind of roll and fold them into a bundle. They should be about 3 times as long as the hook shank. Then just snip them free. Not exactly precise or delicate, but it works.
Tie the butts down to the top of the hook shank just in front of the thread bump. Make sure to hold the bundle firmly while doing this to prevent the feathers from moving while you wrap. I use only 3 or 4 strands of crystal flash on either side of this fly. Licking your fingers and wetting the tips of the flash makes it much easier to tie it in. I like to trim it to the same length as the tail. Some people go with more flash than this, but I like to keep it to a minimum.
Repeat the process with 3 or 4 strands of medium flashabou on each side. This, I snip just a bit longer than the tail. As you'll see at the end of this video, the flashabou really looks great underwater and adds a lot to the fly.
Although you really don't have to, most tiers will cover the hook shank with some type of braid, usually in silver or pearl.
For the bucktail front of the fly, I believe most tiers go way too heavy. Just snip a small clump from the tail, strip the shorter bottom fibers out and then measure it against the fly so it goes about halfway down the tail.
You need to cut the butts off at an angle to get a tapered head on the fly but rather than cutting them off like this, where no matter how sharp your scissors are, they'll want to push the butts away and make a long angle, instead carefully point your scissors back toward your fingers which will ensure a straight cut.
While holding the bundle firmly in your fingers, place it on the far side of the hook with the long end of the angle on the hook shank and take 3 or 4 wraps to secure it. Now repeat the same process and tie in a bundle on the near side of the hook, again with the long end of the angle against the hook shank. With your thumb and index finger, gently spread the bundle around the hook shank and tie it in securely.
Select a slightly larger clump of darker colored bucktail, here, chartreuse, and cut it free from the tail. Once again, remove the shorter butt fibers and line it up so it's just slightly longer than the lighter bucktail. After making the same kind of cut, place it in the same manner, right on top of the hook shank. The white bucktail should support it and keep it from rotating as you take wraps. Once again, use your fingertips to work it around.
A little red crystal flash is usually added to represent gills, blood or whatever. Double a few strands over and then double them over again around the thread. Once you've got them secured to the underside of the hook, give them a snip right at about the hook point. You can then build up and finish the head of the fly.
Eyes always look good but are not necessary. Some tiers go to great lengths to get the tail feathers perfectly aligned but I've never really found this necessary. If you just can't stand such wild looking feathers, try running the fly under hot water for just a few seconds. As you can see it will take on a sleek, flat profile. Lay it out to dry and in fairly short order you'll have nice straight tail feathers.
But, as you can see here, when the fly is underwater where the fish are, the tail feathers just kind of do their own thing which I believe is one of the reasons the pattern is so effective.