Here is the SBS for a great fly that is like a Senko. It's a big worm with great action. I discovered this pattern at a local fly fishing show. A gentleman named Rich McElligott came up with it and he is the Executive Director of the Illinois Smallmouth Alliance. I am not sure what he calls it so I have dubbed it the "Senko Fly"
Hook: 1/0 wide gap worm hook (regular bass hook)
Thread: 210 Denier (match color to fly)
Body/Tail: Patons Bohemian Chenille
Start by cutting 2 pieces of chenille. 1 piece at 9" and the other at about 5"
Next, using a lighter or candle, melt one tip of the 5" piece of chenille. This is just to keep the tail from fraying
Now, placing the hook in the vice hook point up (pay no attention my photo that shows it down) start your thread at the eye and end with the thread against the corner of the bend
Take either piece and tie it in on either side
of the hook
Next tie in the other piece on the opposite side that you tied in your first one.
Once both pieces are tied in, pull both pieces back past the hook bend making sure that the hook is surrounded on both sides. Then pinch both pieces with your fingers.
Next, leave a little bit of slack in the chenille between the hook point and the hook eye and use a clothes pin or other clip to hold the chenille to the hook.
That should leave you with two pieces of chenille dangling off the back of the hook. If you are right handed, hold the shorter piece with your left hand and using your right hand, wrap the longer piece 6 times starting at the hook and going towards the tail around the shorter piece in your left hand.
Then wrap it 6 times forward.
Note: The wraps will only go back a couple of inches and not all the way to the tail.
Next, remove the clip and continue wrapping between the longer piece of chenille around the shorter piece between the hook bend and the hook eye. This takes a bit of nimbleness until you get past the hook point. The good thing is that this won't unravel if you have to let go for a second.
Wrap all the way to the hook eye.
Once you get to the hook eye, tie it off with a couple of wraps, cut the excess chenille away, and build a nice head.
Whip finish and cut the thread.
For the final step, take some watershed - or similar product - and apply it to the last inch of the tail.
This allows the fly to have a tail up stance when falling through the water column and resting on the bottom.
Let the water shed dry and catch some fish!
Overall, it's a pretty easy tie and takes minimal material. You could always add weight to the nose to get it to the bottom a bit quicker but a ton of strikes come on the fall!
Also, please excuse my crappy pictures and the messy tying bench! I've been in a tying frenzy as of late and haven't had much time to reorganize