The concept of a Fly swap is simple. A group of fly tyers get together and tie a given number of flies. The flies are put into a pool - and each tyer receives 1 of each fly tied for the swap!
So - in short - you tie 10, and you receive 10 different flies in return. It's a great way to see some new patterns - and have some new flies to start tying!
So - some short do's and don'ts!
Get your flies done on time! - If you don't have yours in on time - everyone waits for their flies!
Mark or tag EACH fly for your swapmaster! - It will save time for the swapmaster - and inform others of the pattern name - and the tyer once they receive their flies
Provide a container with your flies. This way - if the swapmaster doesn't have a special container planned - he'll/she'll have a container to return your flies to you.
Lastly - if you are remote from the swapmaster - include some form of pre-paid mailer to get your flies back - unless the swapmaster indicates otherwise.
You can also refer on-line to Ranger Bob's most excellent guide to hosting and participating in a Fly Swap in his article entitled 'What Are Fly Swaps?'