When you walk in, you see the window. When you sit on the couch, you see the walls. In a small apartment, those are the surfaces that make it feel like Christmas, and they use no floor space at all.
Windows
A lit garland around the frame. Run a pre-lit garland (on Amazon) along the top and down the sides with warm-white lights woven through. Three removable hooks per window are enough. A 6-foot garland frames a standard 36-inch window with a little left over to drape at the corners. From outside, it glows.
Paper stars. Three to five folding paper star lanterns (on Amazon) in different sizes (one around 24 inches, two around 16, two around 10), hung at different heights on fishing line or thin ribbon. At night with a bulb inside, they’re the best thing in the room.
A wreath in the middle. Loop a wide ribbon over the top of the window and close it in the frame, no hook needed, or use a suction hook (on Amazon). Smaller than you’d think: 18 inches looks right on most windows; 30 looks like it’s swallowing the glass. Eucalyptus sheds much less than pine.
Candles on the sill. Three or five LED pillars at 4, 6 and 8 inches, grouped toward one end, all the same finish. LED near curtains, always, and on a timer so they light up at dusk.
Snowflake window clings (on Amazon). Peel and stick, nothing left behind. Cluster them in one corner, thicker at the edge and thinning toward the middle, like frost.
Holiday curtain tiebacks. Replace your usual tiebacks with deep red or green velvet ribbon, maybe with a sprig of faux berries tucked in. Three minutes, and your everyday curtains look seasonal.
Walls
A washi tape tree. Outline a tree about 5 feet tall with tape (on Amazon), add a few horizontal branch strips and dot it with small stickers or paper ornaments. Green on white is classic; gold on a dark wall is striking. It peels off in January without a mark.
Christmas prints in your existing frames. Vintage botanicals, simple lettering, winter landscapes. The frames stay up; only the paper changes. Store the prints flat between two pieces of cardboard so they don’t curl.
Three small wreaths together. Wreaths around 12 to 14 inches, hung at slightly different heights over the couch or a console, in three different greens: one eucalyptus, one with berries, one plain. Full-size wreaths are too big for a cluster.
A fabric panel. A roughly 3 by 5-foot piece of deep green velvet or red plaid hung from removable hooks or a tension rod. Let it hang a little loose so the folds catch the light. It folds into a drawer afterward.
Your photo wall, slightly dressed up. Tuck sprigs of faux greenery behind two or three frames, put a tiny wreath on one corner, or drape a short berry garland along a picture ledge. In January, pull the sprigs out and the wall is exactly as it was.