A sign is wall art with an opinion attached. It's not trying to be subtle, it's a word or a phrase or a name doing a job, pointing at a door, naming a room, telling a story about the house, and giving a wall something to say instead of just something to look at.
Sizing is where most of these go wrong, because people buy for the wall instead of the spot. Measure the actual space first, not the wall in general, so if it's going over a console table or a bed, the sign should run narrower than the furniture underneath it, not wider, or it reads like it's floating loose. For an entryway or a narrow hall, something between twelve and twenty inches wide usually sits right without crowding the door frame or the light switch. For a bigger stretch of wall, over a dining table or a sofa, you can go up to thirty inches or more, but hold it up with painter's tape before you commit to a hook, because what looks right on a screen often looks oddly small or oddly huge once it's actually up there. The mistake I see most is hanging it too high, treating it like a piece of fine art instead of a sign, when it should sit closer to eye level or just above the furniture it's paired with, so you can actually read it without craning your neck.
Color and finish matter more than people expect from something that's mostly letters. Painted wood in a soft white, cream or black reads calm and doesn't fight with anything else on the wall, while a natural wood tone with the lettering routed or burned in rather than printed on tends to age better and feels less like a craft fair impulse buy. If you've got none of these yet, start with something plain and declarative, a word or a short phrase rather than a long one, in a neutral finish, so it works in more than one room if you move it later. A well made sign has some weight to it, the wood doesn't feel hollow or flimsy when you pick it up, the edges are sanded smooth rather than sharp or splintery, and the lettering is carved, routed, or properly painted rather than a sticker you can pick at with a fingernail. Check the back too, a solid hanging bracket or keyhole slot beats a flimsy wire that'll bow under the weight over time.
What a sign won't do is carry a room on its own. It needs other things around it, furniture, light, a little clutter of real life, or it just reads like a word stuck on an empty wall.