I used to write for one for a year, here in the US. It was really fun, and interesting, because all of the contributors besides myself were NOT zinesters, but just people who enjoyed writing/paper/mail, etc. So one person did a block print every month, one person poetry, etc. The thing I didn’t like about that one was that you had to pay to be a part of it. The “dues” then paid for postage and a bit of money to the person who was in charge of collecting and mailing stuff out. That’s all fine and good, but there were a lot of “non-contributors” who were on the list whom I felt should have paid for everything while contributors “paid” by contributing.
I’m also part of a collaborative zine called “Cuneiform” which is similar to an APA. Every three months about 10 of us mail contributions to one central mailer who then puts it all together and mails us out a zine of all our stuff. It’s really cool and fun, and pretty open if you, or someone else, wanted to join in. msg me if you’re interested.
APAs are cool, as most of the time they are done by non-zinesters, but people with similar interests. There are a lot of different styles of how to do them, and lots of people who know more about them than I do.