White Furnishings: When instant brightening is required, white furnishings are the visual equivalent of adding bleach to a pile of laundry and hanging it in the sun. Fresh and crisp, white upholstery has the added bonus of looking incredibly luxe.

Reflective Floors: Natural stone, particularly these stunning, large slabs of Statuario Venato marble, have a finish and color that subtly amplifies the light.

Low-Slung Furniture: There’s a lot to be said for keeping a low profile. Furnishings that don’t have high backs won’t obscure a window, and they also make the whole room look more spacious. The fluid seating provided by benches is a smart choice for parties as well.

White Walls: Take a page from Scandi design. White walls are the simplest solution when brightness is required, stat. A fresh coat of paint can make a small room feel not only brighter, but larger.

Light Hardwood Floors: The design pendulum is always swinging on floor finishes, from the rage for chocolate-y wenge to pale, silvery barnboard grey. A blond wood floor is a classic that makes white walls seem gallery like and the whole space feel airy.

Mirrors: It’s an easy way to add depth, and sparkle, in small rooms. Hanging a large mirror is a quick way to brighten a room, but consider insetting mirrors into paneling or painting the frame to match the wall, for a seamless and even grander effect.

Lucite: Here’s one material that can literally do a disappearing act. A chic Lucite table is lightweight and practically invisible so light flows through it, just like magic.

Open-Concept Space: Removing a wall opens up a world of possibilities in a dark interior.

Layered Lighting: Pendants, sconces, task lights, bring ’em all on to improve brightness. A bedroom can be blessed with loads of natural light, but benefits from a stunning crystal drop pendant, and articulated wall sconces that can easily be adjusted.

Hidden Shades: Discrete automatic shades squeeze out every available inch of natural light and tuck out of the way so there is nothing between the sunshine and the interior of this glorious bedroom, until night falls.

Source: https://houseandhome.com/gallery/15-things-will-brighten-space/