I stood in a rental with white walls and a lease that forbid paint, staring at the blank stretch above the couch, and realized the whole room felt unfinished because there was nothing on that wall for the eye to land on. One frame later, the room had a point of view.
The difference between a print that looks good for years and one that looks sad by spring usually comes down to what's holding it. Paper matters more than people expect. A thin, glossy stock catches every bit of glare and starts to curl at the corners within a year, especially near a window or a radiator. A heavier matte or cotton rag paper lies flat and takes light without throwing it back at you. Frames are the other half of it. Real wood, even a plain oak or ash moulding, has weight and warmth that plastic can't fake, and the corners should be mitered clean with no visible gap or glue line. Glass over glazing film, every time, if the piece is going anywhere near sun. And whatever you do, don't trust the little sawtooth hanger that comes in the box on anything larger than a sheet of paper. It will hold for a month and then let go at two in the morning, which I can tell you from experience is a specific kind of unpleasant sound.
If you're starting from nothing, go for one larger piece before you go for a gallery wall. A single frame at a good size, something you can see clearly from the couch or the doorway, does more for a room than five small ones scattered without a plan. It gives the wall a reason to exist and it's far easier to get the hanging height right on one piece than on a cluster. Once that's up and you've lived with it a while, the smaller additions make more sense, because you'll know what the room actually wants next to it.
Where it struggles is in rooms already busy with pattern, a heavily tiled kitchen backsplash, a loud wallpaper, a wall of built in shelving crammed with books and objects. Art needs a bit of quiet around it to read as art rather than clutter. Hallways and stairwells are the exception, they can take more than you'd think.
Measure the wall space first, then buy to that, not the other way around.