Q: After you've made the overlapping pleats, that turns 30" of fabric into about 15", I'm guessing...
A: With non-overlapping pleats ( the way I used to do them) it would be about 10-12", because I would have 5-6 pleats, each using about 6" of fabric. (That is, for each ~2" that was visible on the "top", there was another 2" going backwards underneath and 2" going forward. I hope that makes some sense!) With overlapping pleats, I tend to make fewer (usually 3-5) but they are larger, so each visible 3" has 6" underneath it, plus another 1" overlap with the next pleat. So I think it ends up being about 8" at most.
Q: ... but then the picture you have has the pleated section fitting nicely through the 2" rings?
A: When you put the pleats through the rings, they'll naturally bunch up more -- I should probably change the picture so it's not so regular-looking. The pleats tend to fan out from the rings, sometimes as much as 180 degrees, depending on how much fabric there is.
Q: I think I missed a step, do you keep pleating it down or something, am I being dense? I read the Maya wrap instructions so I'm envisioning the 8" end to need to be 4" to fit through the rings and be sewn in place.
A: It really doesn't need to be that small to fit through. the bulk of the fabric will be there no matter how wide the pleated/folded section is, so it's just a matter of how much it will spread out once the rings are sewn in.
With very thick fabric that doesn't fit well through the rings, I sew in the pleats, about every 2.5-3", and actually cut off the material on the inside of the pleat. Because of the way it's folded over, the raw edges never show; the shoulder spread is preserved, but there is much less material actually going through the rings. I've only tried this with fleece or thick jersey, though, not wovens.
Q: But I really like your pleating idea so that it won't dig into my shoulder. (I currently have a Nojo that is apparently much too big and is killing my back, I'm not liking the idea of a sore shoulder to go along with it)
A: It's actually possible to make a sling without pleating at all; Jenrose makes hers out of knits and just stuffs the fabric through the rings. It sort of ga thers itself naturally, though you end up with a much, much wider shoulder than with mine, which I found a bit annoying because it would cover my entire upper arm down to my elbow, limiting the movement in that arm. I like the pleating because it seems a good compromise between not enough and too much fabric spread, but there is the same amount of fabric going through the rings no matter how you do it; it's just a matter of how neat it looks and how it affects the shoulder.