My online art group has another 'mingle' that I think is really fascinating. Each participant is to create a 4 in x  6 in background and mail it to the assigned partner. The partner then collages an altered  page on that background and mails it back to the originator. Here is the background that I made for my partner. I'm anxious to see what she will do with it

If this works out well, I might try exchanging with other art friends to see what they do, and then bind it into a friendship exchange book.