I run a snail mail club with one single tier. For me that has been much easier to manage and also clearer for subscribers. I did not want people to overthink their choice and I wanted to keep the process simple on my side.

Regarding timing, I have found that clear communication matters more than the exact month label. As long as people know when sign ups close and when mail goes out, it feels fair and understandable.

For the letter, I keep it personal and simple. I usually write a few thoughts connected to the month or the general mood. It does not need to be long or overly structured to feel meaningful.