Start your thread and wrap down to just above the hook barb.
Tie in 3 Biots for the tail, one on either side of the hook shank, and one on top, all with their convex sides facing the hook shank so they flair out slightly when you apply tension to the thread wraps. Wrap back towards the hook eye and tie in your burned mono eyes, taking care to leave enough space in front of them to complete the head and whip finish without crowding the hook eye.
Take the thread back to just in front of the tail and tie in a piece of yarn. A length of around 30cm is usually long enough to complete the underbody of a #8 fly. As yarn is a cheap material, I would suggest that you rather tie in a length longer than you will need, and waste some rather than finding out halfway through wrapping the underbody that the piece is too short to allow you to create the correct profile.
Take the thread forward to the point where the nymph's abdomen will effectively start. Create the underbody of the fly's abdomen by wrapping the yarn forwards and backwards along the hook shank to create the correct profile as shown in the picture. Don't make the underbody too bulky as we will still be adding further bulk when we dub the fly. When you have completed the underbody, tie off the yarn and trim.
Prepare your dubbing to be used for the fly. It is important to note that this pattern uses a lot of dubbing and so it is important that you mix enough. To create a colour I have found to closely match the specimens I've collected on our waters here in KZN, I blend the following types and colours according to the following proportions:
3 Parts Spike Guard Dubbing - Olive
1 Part Spike Guard Dubbing - Black
1 Part Spike Guard Dubbing - Brown
1 Part Flashabou Dubbing - Peacock (You can also use another Peacock coloured synthetic dubbing such as Spirit River Diamond Brite.)
Once you're prepared your dubbing, take the thread over the underbody to the point where you tied in the tail. Create a dubbing loop, wax the loop and place tufts of dubbing into the loop. Once you've got the dubbing evenly distributed inside the dubbing loop, pull the loop tight to close it, and twist it into a rope using your dubbing twister, then take your bobbin forward over the underbody to just in front of the abdomen.
Wrap the dubbing rope forward over the yarn underbody in touching turns ensuring the underbody is properly covered, with no visible gaps. Stroke the dubbing back with each turn to avoid trapping it. Once you reach the front of the abdomen, tie off the dubbing rope and trim. Make several half hitches to secure and then cut your thread.
Take the fly out of the vice and give it good brushing to remove any loose dubbing, as well as to make the fibres stand out perpendicular to the body. I find an old toothbrush works well for this purpose.
Using a sharp pair of scissors, trim the dubbing so that the correct shape abdomen is formed as per the photo. Once complete, place the fly back into the vice and reattach your thread.
Prepare your wingcase by cutting a section of Turkey feather, slightly narrower than the hook gape, and coating it with Dave's Flexement. Once it is dry, cut a V out of one end. This will form the wing buds at the back of the wingcase.
Tie in the wingcase as shown with the wing buds extending a little way over the abdomen as shown.
Tie in a bunch of Partridge hackle fibres on either side of the thorax to form the legs.
Spin a noodle of dubbing onto the thread and dub the thorax and head of the fly.
Pull the wingcase forward, between the eyes and secure. Whip finish, apply head cement and you're done !