I've got a magical refugee camp in one of my games here on the board. I don't think I've done anything special, just filled it as it seemed appropriate.
Do I need to just make a bunch of aspects to try and bring this place to life? one aspect being one person? or come up with a bunch of "full" NPCs?
Hold your horses there, I think you might be going about this a bit backwards. Aspects are mechanical representations of things that are there. But the things are there whether or not there are aspects representing them.
So when I went about creating the refugee camp, I started out with the main character, the woman who owned the land. She's the mother of one of the characters and a pretty powerful psychic, so she new there would be the need for a refugee camp, which means she had time to plan. And I've pretty much just worked from there. Since she's had time to plan, there's already some supplies and allies there who started building the camp. But since they also don't have too many resources, it's not too much. A friend of hers looted his army surplus store to get things going, a few minor talents who already felt the need to get to a safe space, and they started setting up tents, building up minor magical security, and so on.
When the players arrived, I had 2 characters fully fleshed out. One of them was Mary, the owner, the other, Susan, was a witch who basically took over the coordination of setting everything up, so the players kind of ran into her pretty quickly. Everyone else was not set up at all, other than "there are a few more people there". Well, and the characters coming with the group that had already been established, of course. I think there were 2 of them at the time, one more later on.
When the players needed an expert in magical disguises, that was basically a team effort to bring them to life. It was well established that there were lots of witches and minor talents in the camp, some where already there, some brought there by the group when they rescued them. The players asked for someone to help them, since none of them was really good at something like this, and a successful rapport roll later, I fleshed out a group of witches who were good at creating disguises like that.
I don't think I've ever even put an aspect on the camp. The characters are fairly well fleshed out, sure, but the camp is mainly a bunch of descriptions, since it hasn't become important enough to make use of aspects like that.