Studded leather cushions - modeling approaches

So, as part of a larger scene I'm working on, I've been beavering away at some props before tackling the larger structural elements of the scene, and one such prop is a studded leather Chesterfield captain's chair.

Now, the wooden parts are very straightforward, but it's the actual studded leather parts of the chair that are giving me a headache, specifically the parts circled in this image:





Now, I'm trying to bear in mind the surface topology with a view to chamfering certain verts and insetting / extruding them to produce the studded buttons, but I'm a bit stumped as to the way I should approach the initial shapes / primitives to give me the geometry I need.

Here's what I've got roughed in for the seat cushion, both isolated and how it fits with the rest of the chair geometry so far:








Would you say I was on the right track in terms of starting geometry, or is there a more optimal way I could approach it? I've got to say I haven't even thought about how to tackle the padded backrest cushion yet.

How should I approach these shapes? I'm fairly sure I saw a tutorial dealing with this kind of shape before, but after some searching, I've yet to find it (unless I imagined the whole thing during one of my ether-induced hallucinations).

As always, thanks in advance.