I remember standing in the upstairs hallway, the one that connects the three guest rooms, with a stack of frames leaning against the wall and no clear plan, and the second I hung a plain black frame around a simple botanical print the whole hallway stopped looking like a corridor and started looking like a place someone meant to design. That is the thing about framed art that posters and canvas prints never quite manage. The frame does half the work before you even think about what is inside it.
Wood frames warm up over time, especially oak and pine, they take on a bit of a glow in sunlight and show their grain more as the years go on, which I like, though you have to dust them properly, not just swipe the glass, because the stuff that collects in the corners of a frame will drive you up the wall if you let it sit all winter. Metal frames, the slim black or brass ones, stay cooler looking and don't age much at all, they just need a wipe now and then, but they will show fingerprints if you're hanging them somewhere low enough for guests to touch, which mine learn the hard way every single time. Keep framed art away from direct afternoon sun if you can, the color underneath will fade unevenly and you won't notice until you move it and see the ghost outline on the wall behind. Bathrooms without a fan are a bad idea too, the damp gets into the mat board and warps it, I learned that one in a guest bathroom that never had proper ventilation, and the print came out looking like it had been through a flood.
When you're buying one or picking it up at delivery, check the glass isn't the cheap reflective kind that turns the whole thing into a mirror depending on where you're standing, run a finger along the back to feel for a proper hanging wire rather than just a sawtooth hook if it's anything heavier than a postcard, and look at the mat board edges, a bad cut there looks fine from three feet away and sloppy the moment anyone leans in close. A slightly crooked frame on delivery is usually just the packing, not the piece, so don't panic over that one.
This is for a home where the walls have been bare a little too long and someone finally wants a room that looks finished rather than just furnished.