For years I bought living room tables the way I buy most things, which is to say I stood in a showroom, liked the look of it, and never once thought about how I'd actually use it. Ended up with a glass coffee table so low and so see through that it functioned mainly as a shin trap and a surface my kids pressed every greasy finger they owned into. What fixed it was finally measuring my own room instead of trusting my eye, which apparently cannot be trusted at all.
Color wise, the easiest finishes to live with are the ones that don't show every ring and scuff on day one, which rules out high gloss black no matter how sharp it looks in the store. A warm wood tone, a weathered oak, a matte walnut, hides dust and watermarks far better and still looks intentional next to almost any sofa color. Light woods and whites are lovely until you have a toddler or a red wine habit, so know yourself before you commit. For sizing, the rule that actually works is to measure the distance from your sofa to where the table will sit and leave about fourteen to eighteen inches of walking room, then check the table height lands close to your sofa cushion height, give or take an inch or two, because a table that's too low makes you lean forward for everything and one too high just looks like a mistake. The other measurement nobody does is width. A coffee table should be roughly two thirds the length of your sofa, not the same length, or it starts looking like a dock. Side tables get forgotten entirely and then someone's drink ends up on the floor.
In an ordinary room, a good table sits happily with a rug underneath it, legs either fully on or fully off, never halfway, and it should feel solid when you set a mug down, a proper thud rather than a hollow knock that tells you it's going to wobble inside a year. Pair a sturdy wood table with a soft sofa and it balances the room instead of fighting it, and if you've got one good anchor piece already, let the table be the quieter one.
The detail that makes a table worth living with is a lower shelf you actually use, not for show, but for the real stack of mail, remotes and whatever book you're never finishing, so the top stays clear enough to put your feet up without apology.