I've been reflecting on this a bit. I found it very useful to have a well-defined project and focus the learning time on things that are necessary for completing it. Having a background in coding was useful because I find you end up developing a knack for isolating parts of systems and figuring out how to work on small parts that end up fitting together.

I therefore focused initially on simply getting readings from a single potentiometer; if I could do that then I felt pretty confident I could read from four of them. If I could generate a midi message I was pretty confident I could send it to something that could read it etc.

When I started on the PCB design I had a simple circuit already so it was a case of translating that onto a board.

I didn't get too deep into any of the various parts but I found that it gave me a birds-eye view of the whole process and I now feel confident in isolating parts of them and 'zooming in' to them and refining them, building on the foundation I've developed.