Each person we meet is very different, even if at first they fall under an umbrella like lawyer, brunette, or teen. As writers we can use this to our advantage. But in our case, we want each character as different as possible.
One way to keep them sorted is to add tags.
• Names must never start with the same letter or sound similar. The more different they are the better. If you can chose one with heritage undertones or deeper meanings, it’s all to the good.
• Appearance—it’s the differences between the cast members that make each player stand out. So if everyone has brown eyes but one, she’ll be the tagged with blue eyes, ignoring the rest. Another may have a dimple, a limp, or a crooked smile. There’s more. What about—scuffed boots, torn jeans, creases as sharp as a blade, skin scrubbed pink, scruff—these hint at a characters very nature.
• Voice—is as much about what they think as what they say. Like all of us, their words may have a deeper meaning than what comes out of their mouth. Their thoughts and body language might contradict what they say. For example if they lie constantly, let them think the truth and speak the lie. Let the contradictions flow, favorite sayings flourish, impatient interruptions break free.
o External movement–in one case it could be the stance, always at attention. Where another could be the constant tick above their left eye. Incorporate mannerisms when using stage direction to indicate who they are without outright saying it.
o Internal Movement—includes inner thoughts, visceral reactions. How a character feels is not always how they interact. It might be a shock to see an old girlfriend in wheelchair when she used to be a tennis pro. The raw emotions fight to get out as they politely chat. Because we can slow time down to a crawl, we can let the reader in on the character’s inner thoughts. Let them witness him working out how to bring up the chair, then eventually changing his mind. It hurts to much. He doesn’t want to know.
When a character is confronted by an action, they will respond expecting a specific result. Give them core qualities that lead them to unique actions/reactions. Not all people respond the same way. It’s usually the odd man out that will bump up the tension.
Hopefully this will give you some ideas on how to make your characters not only unique but easy to keep track of. Play with it. If you have other suggestions please share. I love to read your thoughts.