In terms of gestures, the one thing I do still struggle with is Linux not having a useful equivalent to BetterTouchTool. Whenever I set up a new macOS, that's pretty much the first thing I install. As a result, I'm so used to using a middle click for Expose that even after a year of mostly using Linux, I still find myself middle clicking several times a day and wondering why it's not showing me all the windows.

The closest I've found is Input Remapper, which can help you get your mouse buttons to perform a bunch of things. However, as far as I can tell, it will only allow you to save one at a time, which makes it mostly useless. So I'm forcing myself to get used to the Linux defaults instead.