Check the wiring before anything else. Old fixtures look wonderful and sometimes the cord inside is older than the finish suggests, cracked, brittle, not something you want running hot behind a curtain. Get a real electrician to have a look, or at least an outlet with a plug and a visible cord you can inspect yourself. Once that part's sorted, there's nothing that makes a room feel lived in faster than a light that's clearly had a life before you.
These sit well with the stuff that's already a bit worn in, which is most ordinary rooms if you're honest. A brass desk lamp next to a stack of paperbacks, a glass pendant over a kitchen table with the scratches from actual dinners on it, a floor lamp with a dented shade in the corner of a living room that also has a dog bed and a coffee table ring nobody's bothered fixing. They make sense next to wood that's aged rather than wood that's been distressed to look aged, next to rugs that have flattened in the middle from footsteps. What they don't sit well with is anything too new and too matched. Put a 1960s milk glass lamp on a brand new all white console from a flat pack set and it looks less like contrast and more like the lamp wandered in from a different house and got stuck there. I made that mistake with a school house pendant over a kitchen island that was otherwise showroom fresh, stainless everything, and the light just looked lost, like it was waiting for someone to notice it didn't belong and take it home.
They age the way most old things age, which is to say better than you'd expect if you let them. Brass gets darker and richer instead of looking dirty, as long as you resist the urge to polish it back to showroom shine every few months. Glass shades pick up tiny marks that mostly just read as character unless you're staring at them under direct light. The one real job is dusting the shade and checking the cord every so often, because fabric covered wiring does wear, and swapping a bulb for something warmer toned if the original fixture was built around a bulb shape nobody makes anymore. Don't rewire it yourself unless you actually know what you're doing. I didn't, once, and the lamp worked fine until it very suddenly didn't.
These belong in a home that's been lived in for years already, not one trying to look like it has.