The other day on the Brain Storm Podcast - The Think Tank, we recorded an episode (yet to be released) that myself, +Glen Hallstrom and +Erik Tenkar had brainstormed out our own towns for the listeners.
We put in details like, the name of the town, its location, the type of people, what it looks like (inside and outside), it basic history and key NPCs for the town. You'll have to listen when that episode drops for the exact details of what we came up with but let's talk a little about why its important to have these things jotted down.
For me, I like to have the name of the town, important NPCs and key locations. I also like to have a general sketch of the town layout. My reasoning behind this is that I tend to use my town as a "base of operations" for the players, at least for the lower levels. I believe its a good way for the characters to build up relationships with the town, and give them some roots to a place. If they spend some time in a certain place, they will want to help out, because its almost like their home.
I've experienced other DMs that basically just do towns on the fly and treat them as if "who cares really". We'd go to a town, get a few things, meet a few people and go out adventuring. The game for the day would end, we would meet back up in two weeks, we go back to this very town, names are forgotten, and new names are made back up for those key NPCs we met.
I honestly think its important if you are going to do it on the fly, at least write down the names you decide to assign to NPCs and their locations.
What do you think?