Well, my method of coming up with a comic, Is that i first listen to a song with deep lyrics or beautiful music, i imagine a character that would fit into the lyrics of the song and i imagine how it feels, what happened in its past that made him/her become like how they are in the present.
Also i tend to watch gameplays of almost unknown videogames so i can have an idea of what i want the comic to look like and what feelings i want to deliver the readers/followers.
For example, Petcop its a game or Creepypasta that develops at first in a beautiful environment, but it stills feel strange when you see the protagonist advance, then the atmosphere changes and becomes dark and grimm, like if there Is something about it that makes you entirely paralized.
If that Is the feeling i want for my comic, i’ll come up with a story about a character that lived good and have a very normal life, but inside it was a sick minded person, and do horrible things behind closed doors.
I hope that my advice can help you, have a nice day c;