Elie Wiesel
This quote about revision really struck a cord with me. When I'm developing a character in a first draft, I will often include too much information about their past because it is my way of getting to know the character. I will include details about their past relationships, their high school experiences, and other experiences that are important in my writing process, but not necessarily important to the story. I have learned that during the revision process, a lot of these details can be removed and the qualities of the character still shine.
Sometimes what I will try before the writing process even starts is a character biography on a separate sheet of paper. Or, if I have already written a story and the characters seem flat, I will create one of these bios. Even if none of the details from the bios make it into the final draft of the story, it allows me as a writer to know my characters so well that the decisions I make about their actions in the story seem fleshed out.