1. Login to your amazon account and find stuff you want, and then click "Add to List". You can create several named lists, I have one called Faith Swap so that I can keep it separate from my other lists.
2. Go up to the top menu to find your list that you want to share and click it.
3. In your list, click on "More" and then "Manage List"
4. Make sure that your list is set to "Public"
5. Scroll down and make sure that the list is set to 3rd party shippers. Also set other settings as you want them to be (there is an explanation for each setting if you click the little arrow). Then click "Save Changes".
6. Click to share your list. I know my pic has a big "No" on invite, but actually both of those do the same thing when you click them.
7. DO NOT CLICK "View and Edit". Click "View only" and then click "Copy Link". This is the link that you paste into the Amazon thread.
It seems like a lot of steps but it's really not that hard, just a few gotchas that need to be set correctly for things to work right.