But really, it does come down to practice. What works best for me is reading good code in the style I want to follow, figuring out why it’s written the way it is, and then trying to write my own code. It’s a time-consuming process, so I’m cutting a lot of corners in my current Haskell learning, but it works for me.

Also, here’s an interesting paper called ‘A Tutorial on the Universality and Expressiveness of /fold/’: http://www.cs.nott.ac.uk/~gmh/fold.pdf

It was pretty eye-opening for me, as it provided ways to think about how things can be done recursively.