I'm a pretty prominent Cocoa OSS guy: I've always figured that you "just start", but that's a bit like the draw an owl image. So I'll say how I got started. I

I'm a pretty prominent Cocoa OSS guy: I've always figured that you "just start", but that's a bit like the draw an owl image. So I'll say how I got started. I started by dealing with issues on a large project (CocoaPods). I read all documentation then started dealing with issues that were user errors rather than code. It gave me exposure to the devs in a large project, gave a sense of where common problems lay. Instead of directly working on the product I started to expand the tooling around the project, building websites / logos. Eventually it just gets to a point where writing a PR to anyone on any project is no-effort at all. If you really want a one step start: go fix typos in other people's READMEs.