Tip or frog first?
I've gotten good results both ways on my recent rehair work, but some luthiers argue tooth and nail for one way or the other.
Generally I find it easier to cover up sloppy work starting at the tip, but other than that I see no difference. Am I missing something?
I think rehairing from the frog is much safer and easier flipping the hair around the wedge.
Really it is just preference. There are different things to consider when rehairing either way. Sloppy work either way will result in subpar rehair regardless if you see it or not. I prefer to rehair from the tip first.
If they argue tooth and nail, which one do they argue first?
Depends on what they happen to have on hand. Gotta argue tooth if you don't have long nails; likewise, you gotta argue nail if you have no teeth.
You could always try starting in the middle.