Everyone does it a little different. I don't do it to the bend of the hook. I typically leave a long tag end on a blood knot and tie the dropper to that. Once I use up my usable space on that dropper, I snip it off at the knot, and clinch knot a new piece above the blood knot, so that the knot serves as a "stop" to keep it from sliding down towards the point fly.
Main reason is that I often use heavy flies for the dropper, and if you snag it up, you don't typically lose both flies. Also, sometimes if I'm changing weights a lot, I won't put a fly on the dropper at all and instead put my shot there on an open ended dropper piece. Easy to change weights, and if you snag up, they usually pull right off without losing the whole rig.