It is very simple. Once we decide what the type fly we will tie,you would tie one fly for each member of the swap,less one for yourself. Once you finish tying the set,you mail the flies to the swap host. He/she will sort the flies and mail them back giving each member of the swap one from each other member.So if there were 10 members in the swap, you would receive 9 different flies back.
Just a note on swaps. I never fish my "Swap Flies". They go in a separate box for future reference, patterns, etc. They are also useful in seeing my own tying progress. My first swap flies were pretty much limited to boogers and really simple stuff. And they caught fish. I still tie and fish boogers and simple flies, but the quality of my flies has improved greatly.A fly doesn't have to have all sorts of exotic materials and umpteen steps to tie to be a pretty fly and be productive. One of the best producing flies I know of has 3 materials...hook, thread and yarn. The popular egg pattern has caught its share of fish, I garontee!
So you beginners feel free to join in! I'd love to swap flies with you!