The new tiers at my fly tying course table last Sunday had the exact same question. I always put a base of thread down as I am generally tying in a butt or tail but then I overwrap that thread with a kevlar thread which is smooth and slippery, and then go from there. As such I have a base of this kevlar thread which is as smooth as the hook shank and I have never had any problems with the fly falling apart or not getting it packed tight enough. I have been tying Atlantic Salmon buck bugs and bombers this way for 30 years (and the fish have never complained either ).

What I told the new tiers is that you should do it however it feels comfortable and that spinning deer hair takes alot of practice to get the desired consistency of density and durability.

Dwight