Taper your thread loop material

When tying flies and you are using the Petitjean Magic tool or a paperclip or closed cell foam with slits cut into it (they all do the same thing) and you are planning to split threads to create a dubbing loop setup, or when you are doing a dubbing loop to form bodies, make sure you material is already tapered.
You can taper material like CDC, fur, dubbing etc. by simply cutting it shorter on the one end/side whilst in the tool/clip/foam.
The material at the section that will be wrapped first towards the abdomen is shorter than the material that is towards the front section of the body.

When the material is inserted into the split thread, you can all ready spin the dubbing with your fingers in the thread a little, before spinning the thread as well.
This will add strength to the material, as you have applied a little dubbing spinning with your fingers and then the spinning of the thread.

With the shorter materials at the back, the body is automatically tapered and when wrapping the thread, you do not have to space the dubbing with wider thread wraps.
The body of your dry fly or nymph has the same density right through, still with the tapered/cigar/carrot shaped body, without you having to worry about the taper of the body.