realistically, i just have a playlist of music i like on spotify. that said, if you want chill, I'd recommend
Patty Gurdy or
classical.
If you want something a bit more in depth, i'd recommend something like
Saltatio Mortis or
My Darkest Days.
Edit: Wanted to add, if you don't mind international, there's
The Hu (mongolian, the linked video has Jacoby shaddix of Papa Roach guest singing in english).
I can recommend more if i know your current tastes for while you're writing. I listen to a bit of everything from rap to metal to rock to classical to country. It really jsut depends on what kind of scene i'm writing at that particular moment.
*please note all of the above hyperlinks are to youtube.