This is a helpful thread for struggling RPers along with the Creating Personalities thread! Creating a story for my characters is definitely my favourite part of creation but sometimes, I also struggle with inspiration because I want it to be 
different from my other characters. I realize though that having similar traits in your backstory is totally okay. There’s no need to brainstorm a lot tobe unique; actually, the most common things can even inspire uniqueness in some way!
Here is also a tip that will hopefully help you somehow:
- Make it so that the backstory makes your characters’ motivations and reasoning are clear. Give your characters conflict that will spark a potential storyline. Something that will let you develop them through the roleplay. Everyone has motivations and goals in life, and you can totally write that in your biography whatever that may be. This will also keep your characters from being close to a Mary Sue.