My way of tying off the hackle on a parachute:
When you have completed the last wrap of the hackle, unwind the last wrap, strip off hackle barbs where the end will be when re wrapped. This leaves you with only a stem, no barbs to mess you up in your tie off. You can even add dubbing to the thread if you need to fill in the thorax. Yes, a bit difficult but with practice and patience will make you a nice fly.
Hope this helps.

Denny