Writing a scene and having the audience know which character you're talking about can be tricky. I normally write in the third person but I've struggled with this in first person perspective as well.

It's difficult to work around not saying the person's name and a lot of the times I put "__ grinned" or "__ laughed" or just "__ said" kinda just describing how they're saying it.

I understand that can get boring and sometimes in climactic scenes it's awkward to put the person's name and we'd rather have flowing dialogue.

What I normally do in these situations is flow with what I've been doing. So say throughout the chapter or conversation it was Scar and then Mumbo and then Scar again. You can continue with that flow so people know who's talking.

If that gets confusing, often I'll end up having the character say the other's name.

EX:

"Come on, you never go!" Scar whined and Mumbo sighed as he sat next to him at lunch.

"I'm a senior, this is my last homecoming, you gotta go." Scar said and Mumbo shrugged.

"It's just not my thing. Besides, I gotta rest to- "

"Prepare for tech week? Then how come I'm going?"

"Scar, we all know you're insane."

"And full of great ideas. Like the idea of you going to the dance."

Mumbo groaned and Scar grinned.

~

So we see Scar start out the conversation then Mumbo speaks, Scar cuts in, Mumbo talks again (and we know it's him cause he says Scar's name) and then Scar finishes the conversation.

Personality for the characters is different. OCs is just experimentation and trial and error, but fanfiction is a bit easier since you already have a starting point. Obviously we all love putting our personal touch in and it gets easier as you get to know the character.

For example, I always have Mumbo in the journalism club and I write Martyn to be obsessed with DDR and be a natural theatre kid.

However, if you have a character like Jimmy or Scar (aka the naturally more um...I'll just say cringe characters) it's a bit tricky to not gag when writing fluff with them.

Fluff is just meant to be cliche and cringe so you can't really avoid that, but you can work around their quirks.

Again, this comes with getting to know them and how you like to write their character but I would make sure that it's not too like...clumsy girl energy.

Scar always seems to be that clueless comedic relief and I often write him that way, but he also has those moments where he's nice and aware of other's emotions.

EX:

"You have a great imagination, Bdubs. You don't gotta try and push it down." Scar said, frowning slightly.

"Scar, you can't just have that child side anymore. It's probably gone now anyway."

"I doubt it." Scar chuckled.

Bdubs raised an eyebrow and Scar smiled.

"I'm not being mean; I'm just saying that you still have that childish personality. You don't just suddenly lose it when you become an adult."

"It's not as easy, though."

"Maybe not." Scar shrugged and he stood up. "But it's not impossible."

~

It's just a matter of knowing how you'd like to write them and balancing their funny goofy personality with those soft moments. Sometimes the people who are always happy and laughing have the most going on in their life.