Thanks :D
But normally for me it matters with emotion along with what music I'm listening to. If you like, listen to music then think of a topic. For example, my new Ben x Jeff story, Rainbows Across The Sky. I got inspired by the fact there weren't many transgender Creepypastas but I also listened to music like Rolling Girl and other songs.
So I would base what you write off of things you know and attempt to get inspiration from songs or those around you
When doesn't really matter much.