Creating a distinctive look that isn't a knockoff of something else

[Culhwch]

...or describe some of the surroundings (AKA "world-building")...

You could argue that describing styles of dress is worldbuilding, though. It's certainly something I give some deal of thought to, and try to include in my descriptions where possible. I tend not to execute these descriptions as well as I would like, most of the time, but I still think it's a great way to set the scene, and particularly to quickly establish the standing/geographical origin/personal taste/etc of a character.

 

[Chinook]

You could argue that describing styles of dress is worldbuilding, though. It's certainly something I give some deal of thought to, and try to include in my descriptions where possible. I tend not to execute these descriptions as well as I would like, most of the time, but I still think it's a great way to set the scene, and particularly to quickly establish the standing/geographical origin/personal taste/etc of a character.

Agreed. It tends to be a subtle thing though. As most of us realize, there is no hard and fast rule that can't be broken in writing once in a great while, but for most general guidelines, one need look no further than to your favorite published author(s) for examples.

 

[MeriPie]

My narrator wears suits. Black suits. Black or white shirts. Black overcoat. Black leather gloves. Why? Because I just can't imagine him picking out a jaunty yellow sweater and teaming it with some stonewash jeans. He cares about his image far enough to wear very nice suits, but hasn't quite got the creativity required for colour or variation. He's trying to be unimportant, unnoticeable, doesn't see himself as worthy of normal human clothes... but he doesn't describe his own clothes very often, so it's just a thing in my head mostly.

The only time he's ever not in his suits and black overcoat is when he's out of his comfort zone completely and wearing something that belongs to the other main character because he drenched his own clothes in blood/whatever. The other main character is a mechanic/Mafia heavy so his clothes are all torn/stained jeans/t-shirts in various sludgy unimportant colours. Again, he wears these things simply because he just wouldn't wear anything else. If at any point he's wearing a suit or something, it'll be part of building up a sense of discomfort and wrongness.

 

[Winter Lord]

With Dresden, the coat does have a function. He has defensive spells worked into it.

If you are gonna give them a prop, come up with a reason why they have it. The walking stick turns into a sword, the coat is a focus for defensive wards, the sunglasses allow him/her to see the Unseen World, and the list goes on and on.