Visit some different locations or recall some you have visited previously; both indoors and write down a factual account of what you see, what you can hear, what you can feel and what you can smell.
Next, decide on a specific ‘mood’ for the setting – is it going to be happy, spooky, romantic, mysterious or dangerous? Now re-write the description of the location, ‘colouring’ all aspects of it to take on the mood you have designated to it.
For example: The museum is an opulent building, with wooden panels and velvet adorning every surface. Glass cabinets displayed Victorian clothes and the musty scent of damp permeates the air.
I’m going to give it a spooky mood: The opulence of the past shrieked entitlement through the echoing wooden panels that hid secret doorways and fingerprints of those long dead. Velvet seats, now threadbare, still bore indentations, as if someone invisible was sitting next to me, while I half expected the musty-clothed mannequins to re-animate under the shadowy Victorian lamps.
Or, to rewrite it with a excited mood: The building was vast, crammed with precious treasures each screaming for my undivided attention. Indentations on the velvet viewing benches told of a many a visitor, equally enthralled with the gorgeous gowns and adornments of our past.