The first piece of wall art I ever owned was a canvas print of a beach I'd never been to, bought because it was the right size for the wall and nothing else about it mattered. It taught me that filling a blank space and actually liking what's on it are two different problems, and I'd solved the wrong one.
Where it goes wrong is usually about scale and company, not taste. A single small frame over a big sofa just reads as an afterthought, floating up there doing nothing, so you either go bigger than feels comfortable or group pieces so the wall has some weight to it. Busy art clashes hardest with busy everything else, a patterned rug, a loud accent chair, shelves full of objects, because the eye needs one thing to rest on and if the art is competing with the room for attention, everyone loses, including the art. I'd also say skip anything heavily textured or glossy if that wall gets direct afternoon sun, I had a piece with a thick varnish finish that threw glare so bad in the evening you couldn't look at it straight on, which is a strange thing to have to navigate around in your own living room. And honestly, art is the wrong fix for a room that's actually struggling with lighting or layout. It won't rescue a dark corner or make an awkward furniture arrangement make sense, it just gets to sit there looking nice while the real problem stays unsolved underneath it. Oversized statement pieces are also a commitment most rentals don't deserve, patch the wall, repaint, and that huge piece suddenly needs a new home too.
Finishes matter more than people admit. A simple black or warm wood frame with a mat around the print is almost impossible to get wrong, it gives the art room to breathe and doesn't fight with whatever's already on your walls. Matte paper or canvas over anything glossy, every time, for the sun reason above but also because matte just looks calmer day to day, less like a product and more like something that's lived there a while. Neutral backgrounds, muted tones, a bit of warmth in the palette rather than anything stark, these are the ones that still look right in six months when the rest of your taste has quietly shifted, because it will.
This kind of thing suits a home where the furniture is mostly settled and you're finally ready to let the walls catch up.