[fatguide]

I always pinch the barbs down on barbed hooks before I tie the fly. That way if the hook breaks while doing this I haven't waisted my time tying the whole fly. I have used barbless hooks and had problems with two fly rigs. I tie the dropper fly tippet directly to the bend of the first fly. Had problems with the knot sliding off the upper fly. The pinched down barb usually always leaves a little nub that keeps the knot from sliding off.

Just my .02