Lighting and texture do most of the work. You do not need a redesign, you need about four things.
Cozy is mostly a lighting problem. A room with one bright overhead fixture will feel cold no matter what you put in it, and a room with three small warm light sources will feel finished even if nothing else changed.
That is genuinely good news, because lamps and candles cost far less than furniture. Here is the short list that does most of the work, and it doubles as your base layer when holiday decor goes up in December.
The Deal NestMelts a candle from above with a bulb instead of a flame, so you get the scent with no smoke, soot, or fire risk. The warm light it throws is the point as much as the fragrance.
The Deal NestA dimmer is what separates ambient light from office light. Put this on a side table, turn it down in the evening, and the room reads completely differently.
The Deal NestReal wax with a flickering LED flame and a remote. Safe around kids and pets, they never burn down, and a cluster of them on a mantel is the cheapest atmosphere available.
The Deal NestTexture is the other half of cozy. A throw over the arm of a couch is both a visual softener and the thing everyone actually reaches for.
The Deal NestPart diffuser, part ambient light. The flame effect gives you a focal point in a dark corner without running another lamp.
The Deal NestA wash of golden light across a wall, which is a genuinely different effect from a lamp. Cheap enough to experiment with and it photographs beautifully.
Start with the dimmable lamp and one cluster of candles. Those two alone change a room more than any decorative object you could buy, and they carry you straight through the holidays.