Doing chores, playing music, playing video games, laying about, walking. I also tend to browse random Haddocks and source code on my phone the same way I browse other websites.
It's mostly a subconscious thing. I can't tell you how many times I've had a Haskell problem to solve (highly-abstract and systems programming alike) and I take a couple days off the keyboard and come back and write code that'll last years.
Of course, there's still a time and place to do the whole tight feedback coding loop thing. But it isn't how most of my Haskell comes to be.
