The moment a PC says 'what does the weaponsmith look like' some GMs start to panic.
NPCs make a game come alive, but also are perceived to require a lot of work. It doesn't have to be like that. Here's a few tips to help.
1. Names! Spend 10 minutes on Google and you'll have list of names appropriate for your setting. Print them off and keep them close to hand. When you need a name, don't flounder, just pick one.
2. Quirk. There are loads of resources; for Pathfinder the Gamesmastery Guide has a number of tables. Roll a couple of dice and let the NPC build himself.
3. Make notes. Write down what the NPC is like. Just a few scribbles will do especially if you have the time later to write them up. Nothing emerses the players in the mundane more than that weaponsmith (you know, the old guy with the burnt forearm) says 'so, killed anything with that masterwork sword I sold you? I put a lot of work into that...'
NPCs are supporting characters in your novel. Have a read of this for some inspiration - http://io9.com/5896488/10-secrets-to-creating-unforgettable-supporting-characters