When writing a novel, how can a character be developed well, but QUICKLY?

Claire, one of May’s three flatmates, former university roommate, and best friend in all the world, shrugged expansively. “It’s a Saturday night. What else would I be doing?”

“Why is that always your first suggestion? I do not need some tea. It’s three o’clock in the morning! If I have tea, I’ll never get to sleep.”

Essentially, what you do is show the character:

Rikishi calls for WWE writers to be fired for botching Jey Uso’s world title run - Cageside Seats

Create a context between this character and other characters.

“So you didn’t meet any cute boys at the club tonight?” Claire called as she bustled about the small kitchen.

“It’s not looking at you.”

Have you ever had a bad gut feeling about someone and it was right?

Engaging in conversation that also shows something about their intelligence, personality, wit (or lack thereof); and

“Thanks. You’re looking pretty ratty yourself. Have you been in that bathrobe all day?”

“Exactly.”

What were Sauron's powers in The Lord of the Rings (LOTR)? Did he have any magic or anything like that?

“But they’re cold!”

“I don’t know. Partying. Going to a pub. Anything besides sitting on the couch reading…” She squinted. “What the hell are you reading?”

“Hang on, are they playing ping-pong?”

Why did Obito, a supposed "bad person," do good things for Kakashi?

May studied the black and white comic panels. “Oh, my. She looks…anatomically implausible. What is she doing to that poor man? Wait, are those cat ears?”

“Tart!”

“Nope, I mean a cat followed me home. A black cat, to be exact. All the way from the club. Probably still out there, for all I know.”

Have you ever secretly watched someone while they were doing something private?

In the kitchen, Claire set out a battered pair of mugs: May’s black, with “PEBKAC: Problem Exists Between Keyboard and Chair” in white letters; Claire’s white, with “This must be Thursday. I never could get the hang of Thursdays” in dark blue. She carried both mugs into the living room. “A moggie followed you home? Is this some weird Internet slang I’m not current on?”

“You know what? Never mind,” May said. “I am way, way too drunk to be having this conversation.”

“May! You’re home late! Early, I mean. Well, I mean, it’s early in the morning, but you’re home before I expected. Er, after. Before?”

It sounds like WWE has an explosive angle planned for SmackDown - Cageside Seats

“Yuuna and the Haunted Hot Springs!” Claire turned the book around.

Do that and you can ground your characters quite quickly.

“No way.”

Do guys ever want to suck a dick even though they are straight?

“They are! He broke the rules of the boarding house by petting this character while she was in cat form, so they invoke the ancient rules of single combat via ping-pong, and—”

They both burst out laughing. “I’m right, though,” Claire went on.

“None of those either. Look upon the wasteland that is my sex life, and see that it is barren. Naught but a moggie followed me home.”

Artists get better with age, e.g., painting. Yet when it comes to pop music, the famous work tends to be written when musicians are in their twenties. So, why aren't Bob Dylan or the Stones banging out amazing tunes now?

“You don’t need a cat. You can’t take care of a cat. You can’t take care of a ficus.” Claire flopped on the other side of the sofa and wriggled her feet beneath May.

“It’s a cat. All cats are weird.” May sipped from her mug, inhaling the warmth. She closed her eyes. The room spun. She opened them again. “Ugh. I think I drank too much.”

“From the look of you, if you try to sleep now, you’ll spend the next three hours hanging onto your bed trying to stop the world spinning. Since you’re not going to sleep anyway, you might as well keep me company.”

What can you do if you are a full-grown adult, but never experienced being a child?

“I’m just a fan of your catch and release program.”

Doing something they enjoy, that expresses their personality, and that is in some way unusual or noteworthy;

After Eunice and I finished London Under Veil, I entered the first chapter in a contest at a convention where you could submit something and have it critiqued by a professional book agent.

Scientists make jaw-dropping find after drilling more than 1,500 feet into Antarctic ice: 'We even discovered a school of lobster-like creatures' - The Cool Down

“I’m serious!” Claire said. “It’s staring straight at me.” She let the curtain fall. “Weird.”

“I’m glad my sex life is so entertaining.”

“Nary a cute boy in sight.”

AMC Theaters to Run Even More Commercials Before Movies Play - Bloomberg.com

“I need to do laundry.”

“Well, maybe if you didn’t spend all day reading—” May prodded the book with its garishly-coloured cover with her foot. “Bizarre comic book porn…”

“Damn straight. So get to it! This time next week, I want to hear some moans coming through that wall.”

Do most men prefer curvy women or skinny women?

“I know! That’s why I’m putting them under you!”

“Well, maybe if you’d wear more clothes, they wouldn’t feel so cold. Hussy!”

May yelped. “Hey! Your feet are cold!”

“No, about the cat. You don’t need a cat. You remember what happened to your spider plant, right?”

“Claire, I—”

“About wearing more clothes? How am I supposed to catch any fish if I don’t show off the bait?”

Claire sat back down, legs tucked elegantly beneath her. “You are looking a bit sloppy,” she said, inspecting May through narrowed eyes.

“Yes way. It’s washing itself under the street light. Uh-oh, I think it spotted me. It knows I’m watching it. I swear it’s looking at me.”

“I’ll put the kettle on.”

The agent had only one bad thing to say (the synopsis was crap; writing synopses is hard!), but praised the characterization and particularly how well we introduced a character’s personality quickly.

Here’s how we presented the character Claire when she was introduced, which the agent particularly singled out:

“I try not to, but thank you for reminding me. I know I don’t need a cat. I don’t want a cat. What would I do with a cat?”

“Claire! Why are you still up?”

“Cute girls?”

“Fine.” May collapsed into the warm spot Claire had just vacated.

May pushed Claire’s feet away. Claire rose to peer out the window. “Huh. It’s still there.”

“Perv.”

“Exactly.”

“Yep!” Claire chirped. “There’s this schoolboy, see, and he’s homeless, so he lives in this boarding house that used to be a hot springs bathhouse, which is cheap because it’s haunted, so he decides—”

“You need some tea!”

“Number one, it’s not porn, it’s ecchi, and number two, why would I waste a perfectly good Saturday doing anything else?” Claire pulled at her tea and sighed. “The only thing that could make this day better is if you'd come home with some cute boy, so that after you kicked him out tomorrow I could live vicariously through you.”