10 Decorating Mistakes You're Making (and How to Fix Them)

Thick drapery can be beautiful, but if it's keeping outside light from streaming in, your room will be a lot less inviting.

The Fix: Hang sheers made of neutral-colored linen, suggests Los Angeles-based designer Shannon Wollack. "They bring texture and warmth, and they're also gauzy enough to let light filter through," she says. "To maximize natural light when you have only small windows in a room, avoid placing any pieces of furniture in front of those windows if they are taller than the sill."

Hanging curtains just above a window's trim, or halfway between the trim and the ceiling, used to be the norm. But the pros say that's a missed opportunity.

The Fix: Hang curtains as close as you can to the ceiling line. "It makes even teensy windows look gargantuan," says Griffin. Width-wise, extend the curtains five inches to a foot past the outer edge of the window trim. "That way you can see most of your window when the curtains are open," she explains. If you're picking out new ones, choose curtains that are about twice the width of the windows. "That fullness helps them drape well and look expertly styled," says Griffin.

A rug that's on the puny side makes a room look fragmented and feel choppy.

The Fix: Go beyond the edges of your biggest piece of furniture. If you have a standard seven-foot sofa, choose a rug that's at least nine feet, which will extend about a foot past each side of the couch, says New York City designer Elaine Griffin. (Stuck with a small rug? Layer it on top of an 8-by-10-foot or 9-by-12-foot solid jute or sisal rug.) For a bedroom, choose one that's at least 1½ feet wider than the bed (an 8-by-10-foot or 9-by-12-foot rug for a king- or queen-size bed and a 6-by-9-foot rug for a full-size bed). In a dining room, pick a rug that extends at least three feet beyond the table on all sides, says Los Angeles designer Timothy Corrigan. "No one likes pushing back from the table and having the chair legs fall off the rug."

Craning your neck to see a piece of art: awkward. "You want your eyes to move around a room in a fluid way, which only happens if you're eye to eye with the art," says New York City designer Suysel dePedro Cunningham.

The Fix: Try Cunningham's hanging trick: "Visually divide the room into four sections horizontally and hang your art in the one that's second from the top. To make sure you get the layout right, trace the frames onto paper, cut those pieces out, and tape them to the walls before you hang the art."

When you have a tight space, your instinct might be to push every piece against the walls. (It opens up room in the middle, right?) A stick-to-the-perimeter plan actually makes a small space feel even smaller, says Tracy Morris, a designer in Washington, D.C. "Breathing room near the walls makes a space feel more expansive," she explains.

The Fix: "Float" a few pieces instead, says Morris. In a living room, set up a conversation area with slipper chairs on a small rug a foot from the wall. "It gives the illusion of a room that's airier and less crammed," she says.

A common misconception is that painting any room white will make it feel bigger and more beautiful. "Sometimes that works," says Los Angeles designer Emily Henderson, "but if the room has very little natural light, white walls can look flat and boring."

The Fix: Try a medium-to-neutral shade to add depth. "Two of my favorites are Portland Gray by Benjamin Moore and Aloof Gray by Sherwin-Williams," she says. "They have soft bluish undertones that change the wall color slightly throughout the day, bringing more life to a space than plain white paint would."

Brighter isn't always better, says Morris. "High-watt bulbs tend to 'blow out' a space, so it ends up feeling cold and stark instead of warm and cozy."

The Fix: Go with 60- to 75-watt-equivalent bulbs in common areas to give off task-level lighting that isn't too intense. In personal spaces (bedrooms, bathrooms), a 40- to 60-watt-equivalent bulb is your best bet—it provides a softer, more atmospheric light that's still bright enough for reading, says Morris. Another common misstep: sticking with a single overhead light. For functionality, that might provide the right amount of light, but aesthetically it falls short. "An overhead can be glaring and feel overbearing in a room," says Mat Sanders of Consort Design in New York City. "To balance it and make the space more inviting, you need a mix of table, floor, or wall lights." Some good guidelines: In a living room with a standard-size sofa (about six to eight feet long), use at least two table lamps, suggests Los Angeles designer Melissa Warner Rothblum. If there's more than one seating area in the room, anchor each with a floor lamp beside a bench or a pair of chairs. In a dining room, opt for a pair of table lamps on a sideboard or floor lamps flanking a console.

When you choose artwork that's too small, it looks like it's awkwardly floating on the wall instead of anchoring the space, which is distracting.

The Fix: There's an easy rule of thumb for hanging art above a sofa or bed. "It should fill at least two-thirds of the wall space above that piece of furniture to look and feel balanced. If you go smaller than that, even if you can't articulate why, your eye understands something is amiss," says Griffin. But that doesn't always mean you need giant framed prints. "You can 'cheat' by hanging multiples either salon-style or in a grid to get that wall coverage," says Griffin. If the pieces are uniform in size, leave an equal amount of space between them; if they vary in size, you can mix it up.

It's easy to feel like you need a whole bunch of throw pillows to make your couch feel cushy. But a big mix usually just ends up looking messy, says Los Angeles–based designer Vanessa De Vargas.

The Fix: Stick with a more streamlined setup. "Two pillows on each end are really all you need for a sofa that looks chic but not stuffy," says De Vargas. "I prefer one big pillow and one small one on both ends, but you could also use pillows that are all the same size."

It's tempting to arrange a sofa facing a window or fireplace, but if that means you're seeing the back of the couch when you walk into the room, it's generally a bad move. "Being greeted by the back of your sofa—and the backs of anyone sitting on it—feels unwelcoming," says Andrew Howard, a designer in Jacksonville, Florida.

The Fix: "Whenever you've got a large wall, use it to ground your sofa," says Howard. It's less jarring to look at the backs of accent chairs because they aren't as bulky. No way around exposing the sofa's back? You can soften the look with a console table in front, styled with low stacks of books or decorative objects.