Take some lead wire and wind down the hookshank. Make sure that there is a gap of around 6mm left between the hook eye and the lead. The same needs to be left at the rear of the hook, again about 6mm, this time from the barb. Once the lead wire is in position, coat the lead with superglue to fix it in place.
Take a bunch of marabou and remove any excess fluff from the stems. Wet the stems and catch in just before the lead. Try not to protrude onto the lead with the marabou, this will keep the body very uniform.
Wind the chenille up the hookshank. After each wind I find it helps to push the fibres back with your left hand using the thumb and forthfinger before performing the next winding. At the thread position secure the chenille with thread and trim any waste chenille.