> 1. My favourite genres are K-Pop and Industrial – it helps that they are also very energetic genres — and my rule is that I can only listen to them while programming. Helps to really put me in the “you’re working now” space (thanks to Julian Shapiro for this tip)

I never consciously did this, other than I obviously went to the music and pressed play, but since about 10 years ago, when I really need to focus on work, I listen to a playlist of what I would call prog trance/house trance, a genre I would absolutely never listen to for the enjoyment of music. It's really weird but it soothes me when working, and it doesn't distract (by me getting too into it), nor distracts me by being annoying.

It reminds me of when I was a teen and I was an extremely tuned night person (still am, but conformed), and was really hard to wake up. Slept through alarm clock at highest setting. I scheduled a playlist on my computer, and allowed it to wake up from hibernation for scheduled events to play through connected speakers. It however ruined any music I used this way, so I had to pick music I didn't like to begin with.