The bead head wooly bugger certainly needs no introduction, it's one of the most popular searching patterns of all time. There are many different ways to tie a wooly bugger, the following method works well for me.
One of my favorite hooks for wooly buggers is a Dai-Riki #700 but just about any streamer hook will do. For this size 10 hook Im going to use a 5/32" gold bead. Begin by placing the bead onto the hook small hole first and then get the hook firmly secured in your vise. Choose a thread in a color to match your fly, in this case, a brown olive. I'm using UTC 140 Denier thread rather than lighter 70 so I can put a little more pressure on the wraps.
Wooly buggers really benefit from weight. Fourteen wraps of .020 wire, in this case, the lead-free stuff, isn't too much. Lead is soft enough, so you can usually just pinch it off but with the newer lead-free materials, wire nips make the job much easier.
Start your thread immediately behind the wire wraps to lock them up against the bead. For added security you can run some wraps over the wire if you choose. For the tail I like to use a single marabou blood quill. Strip off any of the nasty off-color lower fibers. Look at the quill. You may notice that many marabou blood quills are fluffy at the base, but have fine stringy tips. To get just the fluff take a small straight edge, like the back of your scissors, and essentially rip those stringy tips right off. This gives a more natural edge than cutting them off with scissors. If you don't rip the tips off, the bugger will look like the tail on the left. The fluffy tail on the right has had the tips removed.
Wetting the marabou really helps to keep it under control. Measure the tail so its slightly longer than the entire hook and tie it in immediately behind the wire wraps and then snip off the base of the feather. Tightly wrap back to the bend of the hook and then bring your thread all the way back up to just behind the bead.
For the body, try using chenille one size smaller than you usually would. I've cut about a 6" length, and rather than starting at the rear of the fly, tie it in at the bead and secure it to the top of the hook shank all the way back to the start of the tail then, wind the thread forward. Securing the chenille in this manner helps to avoid a nasty bump at the butt end of your fly. Make sure the chenille is well secured behind the bead but try not to take too many wraps.
Now for the hackle. Not all bugger hackle is created equal and I've found the preselected hackles, like those in a Whiting Farms Bugger Pack, although a bit pricey up front, in the end turn out to be a good value. Select a hackle with a fair bit of web at its base and the right size fibers about 2 to 2 1/2 times the hook gap. Remember you'll be wrapping around the chenille and some thread wraps, not the bare shank of the hook so err on the side of smaller rather than larger. Holding the hackle like this, with the shiny side facing toward you, strip the lower fibers from the stem. Then strip about 1/4" of fibers from the top side of the stem to ensure the hackle will wrap correctly. Snip the butt off, leaving about a 1/4" of exposed stem. Using a few tight wraps, secure the hackle immediately behind the bead and then snip the stem off close. Wrap your tying thread back to the start of the tail in a nice tight open spiral. Finish with one or two complete wraps at the base of the tail. Now, grab the hackle with either your fingers or hackle pliers and begin wrapping. Notice how the bare stem helps the hackle to orient correctly. Take one complete turn right at the bead then begin angling the hackle back in an open spiral. If you accidentally let go or the hackle tip breaks, you can usually recover without too many problems.
Take two nice tight wraps to secure the hackle and then either pull or snip the tip free. Being careful not to trap the hackle fibers, wind your thread forward in an open spiral. This is effectively a counter wrap which crosses the hackle stem and will greatly increase the fly's durability. Once at the bead, whip finish the fly trying not to take too many wraps. A smaller thread collar generally looks better than a larger one. A shot of head cement and the bugger's done.
It's hard to have too many bead head wooly buggers; olive, black, and brown are the perennial favorites.