Could someone please explain the fly swaps to me? I mean, does an individual tie one fly for every person that is involved in the swap (all the same kind of fly of course) or what? Im interested in getting into one, but i want to make sure that i know the "rules" per se and dont end up being more of a pain in the back side (lord knows that with throwing hooks we have enough of that already) to everyone else involved. I just need the particulars is all.