So, you need a room description. You don't know exactly what the room will be, but you have a general idea for the feel of the room. Leave blanks and let it fill itself in. This is especially useful if you're running a sandbox game and you don't know where your adventurers are going.
A Little Nervous
You enter the dark room. The windows are mostly blocked with stacks of (Material or good) teetering on top of each other. The whole room smells slightly musty. You hear someone bumbling behind a large oak desk. (Some rooms will have NPCs associated with them). An object falls and catches your eye. It lands softly in a pile of (Something). It was just a (Blank)
This could fill in for most crafts, a thieves den, scribe, clergy, magic shop.
Lush
It's a double door. As you try to open (one or both), you realize you need to put a little extra effort in. The thick plush carpet puts enough resistance on the door to make it difficult. You get it open and get it shut again. Sound from outside instantly dies out. Light cascades from above is that a chandelier, or just a faceted window on the ceiling? This is more than you expected, more than it needs to be.
While that room would never belong to a blacksmith, it might be the quarters of a powerful clergy member, perhaps a noble, a wealthy merchant, or even a corrupt guard. Perhaps it's the back room of a wealthy inn, or the penthouse suit.
Feel free to share any generic room descriptions that you want :)