A pinch on the mop, on the head end, just before tying off, will allow you to pull the excess fluff off the mop and expose the core threads, You can tie them down more firmly, eliminating the raggedy ends. Any space created by that can be covered with dub, to suggest a thorax.
I will vary the bead size but usually in the 3.0 to 4.0mm range. Hook is a size 10. I have also played with using a regular countersunk bead vs. a slotted bead on a jig hook which gives more room to tuck the mop material in at the bead.
