Start your thread one-third of the entire hook length behind the eye. Here I'm using a #2 Mustad 3407 stainless hook. Place a set of dumbbell eyes directly on top of the thread and begin making figure 8 turns to secure and orient the eyes. I like to make several different kinds of wraps to get the eyes attached to the hook as tightly as possible. If you need to, adjust the eyes so they are perpendicular to the hook shank.
Position your tying thread in front of the eyes and apply a liberal amount of your favorite cement to both the top and bottom wraps of thread. Here I'm using "Hard As Nails".
Select a small clump of white bucktail and snip it free from the hide. Holding the tips in one hand, pull the shorter butt fibers out of the clump and dispose of them. If there are extra long tips you should get rid of them too.
Measure the wing so it's about twice as long as the entire hook then cut the butts off at an angle. And now, while tilting the bucktail, place the butt ends on top of the hook shank. Take a collecting wrap or two, and then nice tight wraps to form a gradual slope. Make sure the bucktail is really secured to the hook. Move your thread to behind the eyes and take a couple of tight wraps to pull the bundle down to the top of the hook shank. Then make several open thread spirals down the hook. Make an additional wrap then spiral the thread back up to a position in front of the eyes.
Turn the hook upside down. You're going to have to do this manually if you don't have a rotary vise. If you've got any stray fibers, now's a good time to snip them out.
I prefer minimal flash on my Clousers so I snip only three strands of gold crystal flash from the hank. I will double this over so the finished fly has 6 strands. Secure your crystal flash just in front of the eyes.
Using the same procedure as with the white bucktail used for the belly of the fly, prepare a small bundle of olive bucktail which will form the back of the fly. Again, cutting the bundle on an angle and placing it to the hook shank on an angle, really makes wrapping easier and helps to create a nicely tapered cone-shaped head on the fly. With that done, add a whip finish and give the thread a snip.
Apply a liberal amount of cement to the wraps. For a really durable fly you can use epoxy and a drying wheel.
Snip any long strands of crystal flash. I like the crystal flash to extend just beyond the bucktail.
And there's what the final fly looks like. I like my Clousers tied sparse, like this one and with less flash rather than more but everybody seems to have their own preference.