Many years ago, I read John Steinbeck’s novel THE GRAPES OF WRATH. I love JS and I loved this book.
I remember one scene where the Joads stop for gas and there’s a man who pumps the gas at the station. He had a missing eye and he didn’t wear an eyepatch. I don’t remember if JS described that open socket or if I added my own bits and pieces to it. But 100 years later, I still remember that one detail.
Give one important detail for each of your characters that sets them apart, that makes them unique.
Remember, good writing is in the detail.