Find one of your stories you like and write a story about the same main character, but at a different point in their lives.
Does this affect the original story?
Are you able to keep the character continuity working? (ie does the character change between the 2 stories to fit the story or does the story change to fit the character?)
If continuity is not working what event happened between the 2 stories your readers are missing out on, and should you instead be writing about that event?