The book I'm writing has a lot of characters. By a lot I mean I have 34 named characters so far. I created character plots for the 20 main named characters that will be in the first book. After all that, I'd like to say I've become pretty good at creating character plots.
First, what I like to do for my stories and books is find the meanings of random names or ones I like. If you're writing a more contemporary book that takes place in modern times, you'll want to use normal names, but if you're writing a sci/fi or fantasy book and every part of you burns with the desire to use the name Xenon Astro the Fifth, go ahead. Make sure you're sticking with the theme, time, and setting of your book though. You wouldn't use Xenon Astro the Fifth in a book like "Pride and Prejudice." When I find names I like, I write them all down with their meaning and then put names to faces. I start with my main characters so they get the first pick and then go down the list. You can do this for places and buildings too.
After I sort out the names, I then proceed to the plotting. This first part I learned from Jenna Moreci, who I'll link down below. I'll also post a fake character plot to give you an example but I'll try to explain as best as I can. First you'll want to decide their role in the story, like are they the antagonist/protagonist, love interest, etc. Then create their motivation for doing what they do. Do they try to save the world to protect their one true love? Next, create their life experiences that shape who they are. Were they abused as a child, making them abusive as an adult? Did their parents pass away, leaving them depressed and orphaned? It's best to use a lot of detail here because it'll help you form their dialogue and the next two parts of the plot. Also, don't be afraid to wreck a little havoc on your character's life. Make their abusive parents pass away, leaving them depressed, orphaned, and destined to be abusive to everyone they love. That's what creates the character. Next you need to create their strengths and weaknesses. Is he really smart and intelligent? Is she emotionally strong because of the stuff you should have put her though? Finally, make their weakness. They must have weaknesses, even if you're writing about the most popular girl in her high school. Is she really pessimistic? Does she think too much of herself?
After that main plot, I like to write down all the themes that character will represent throughout the story. Do they deal with sexism or oppression of women? Does your really intelligent guy deal with the quest for discovery? This will also help a lot in creating situations and dialogue for that character.
Now is when I really define their personality. I first sum up that character in one word, for example you could use the words dark or adventurous. Then I'll think of or find a song or a few songs that they would either really like or reminds me of them. Then I write down their typical every day outfit. Does Xenon wear a sparkly space suit or a black one? (I'm gonna go with a black one) Then write down their best memory. You can have them say it during the story, have them think about it, or just use it to help it think like them. Then decide on their biggest fears. You can use these the same ways as the memory. You can also use their fears against them, like J.K. Rowling used spiders against Ron and even made him face one three times bigger than him. Next, create their pet peeves. Do they hate close-minded people? Do they hate surprises? Use these against them too. Now decide on their favorite color. Look up the symbolism of every color and decide which one sums up your character, like blue means calm and relaxed. I like to create a plan for their life too. Like do they want to go to Harvard and study law, or if they're older do they want to be the CEO of their company? Also, come up with something they do a lot. Do they shuffle their feet when they walk to show their low self-esteem? Do they chew on their nails when they're nervous? Finally, create their birthday. I even figure out their astrological sign.
Personally, I think character plotting is really fun because it's like meeting a lot of new and really different people all at once. It sounds insane but it's actually really easy. Hope this helped!
Jenna Moreci Youtube