You can craft a sewing machine and use it to make custom shirts, pants, etc. I think this would be cool on servers because clans or groups can wear uniforms to look organized. It would also make everyone even more unique.
I'm just imagining a system like in animal crossing now. When you click on the sewing machine you go into a MS paint-like screen where you can draw your design.
That would probably work very well for this, although it could be made simpler if it worked in a grid like screen, and you could essentially take thread (of different colors and materials) and filled in an outline of what you're trying to make (shirt, pants, hat, etc.) by hatching or cross-hatching. In case you don't know what I mean, see http://en.wikipedia.org/wiki/Cross_hatching.
"Is that cross-hatching I detect?" Anyway, on topic. I think this would be a cool idea, but where would you get the cotton/silk or whatever is used to make the clothes?
Probably from alien spiders and merchants on city planets. But probably spiders. Anyway, I like this idea! Although I remember Animal Crossing's sewing machine was very fiddly
I'd totally trap a hundred spiders in cages and harvest the silk from them while they were still alive.
I quite like this idea, but what if you could create a completely new clothing item? It could work by having a basic template put on a player model, and then with a MS Paint style interface you could draw the piece of clothing within a certain space. This would allow players to create completely new styles of clothing, E.g. rather than a simple dome-shaped helmet, the player could draw a spike on top of said dome and create a pickelhaube, or extend the base of a t-shirt to make a robe of some sort.
I'm not so sure about this making it into the full game, but definitely as a mod should it be possible.