Start by figuring out what kind of items will be in the round robin. For example, current $1 chips or roulettes or whatever. If they are chips, you need at least 30 chips to make it interesting.

Next, recruit no more than 10 participants. Any more than 10 and it takes forever to finish the RR and get your items back. You will need their mailing addresses and email ids.

Put together an ordered list of the 10 participants with their addresses. It is nice idea to pre-print address labels. Don't forget yourself.

Put together a list of rules about what the Round Robin participants should do. For example: what kind of chips are expected to be in the Round Robin; Post when you receive the RR and when you send out on this board; Use Priority Mail with confirmation to send to the next participant; Don't hold the RR longer than 3 days, etc.

Put together a scoresheet to record what items were in the RR at the start and what each participant took from the RR and what they added.

Put all the lists, the scoresheet, and the items into an envelope, usually a free Priority Mail envelope is best, and sent the RR to the 1st one on the list.

Each participants gets to swap chips in the RR for their traders. At the end the RR is returned to the starter with, hopefully, a nice group of new chips.

And that's a Round Robin.