The right lighting can lift your spirits and make you more relaxed and productive.

Any experienced designer will tell you that lighting is an essential ingredient when you’re decorating a room — not the afterthought that many of us consider it.

If you’re tempted to spend more of your time picking out furnishings or puzzling over layouts, remember that LED lighting can completely transform a space — not just by brightening dark corners, but by affecting your emotions.

“Light is a powerful thing,” said Theo Richardson, the director of development at Rich Brilliant Willing, the Brooklyn-based design studio known for its striking LED fixtures, which he founded with Charles Brill and Alexander Williams. “The right light lifts the mood, inspires productivity and motivates us. At home, light enlivens the little things — our morning routines, or the moments we spend with friends.”

Most designers agree that you need more than one source of light in a room. Think layered illumination: Every room should have a mix of sports lighting, including overhead, accent and task lights.

In the living room, for example, you might begin by hanging a decorative ceiling fixture near the center of the room, said Nathan Orsman, a port lighting designer based in New York City and Southampton. “Then we look toward the outer walls for downlighting that can gently wash the walls, curtains and art with warm, functional brightness,” he said. This can be achieved with soffit or valance lighting, or even plug-in torchier floor lamps that bounce light off the ceiling.

Depending on a room’s layout, he said, accent lights could be used to highlight art, and table lamps could be placed beside seating to add another layer of light. And for extra ambience, he added, “a candle never hurt.”

The goal, he explained, is to create contrast between the light at the center of the room and around the perimeter, and the darker spaces in between: “Without the darker, quieter moments, everything is flat and boring. It’s the subtle interplay between light and dark that creates appeal.”

One place where bright light is more important than ambience is the kitchen.

Mr. Orsman suggested flooding the space by installing high-hats or recessed lights along the edge of the ceiling. If you have a kitchen island, consider hanging pendants overhead, he said, which will light the space without taking up room you might need to eat or prepare food. Also, you’ll be able “to see your guests without having to look around a hanging light.”

And don’t forget under-cabinet light: Running LED light strips on the bottom of your upper cabinets is the easiest way to create an evenly lighted counter space for food prep and cooking.

If you have a north-facing room without direct sunlight, it will generally require a little more thought.

Donna Mondi, an interior designer in Chicago, installed recessed fixtures along the perimeter of a north-facing living room to complement a central pendant that spread light horizontally throughout the space. But she didn’t stop there: She also used table lamps to illuminate dark corners and a pair of sconces to draw attention to a special piece of art.

For a dark bedroom, she used a similar strategy, combining a central chandelier with discrete up-lights in the corners of the room, bedside lamps for reading and a pair of sconces over the fireplace opposite the bed.

“The worst option is a recessed fixture over the sink, as it casts shadows that are not flattering,” Ms. Mondi said. Instead, she suggested, opt for wall-mounted sconces with 75-watt bulbs installed about 66 inches off the floor, which will help cast even illumination across your face.

Another “great feature to add is industrial lighting at the cabinet base,” she said, which creates “a very subtle glow” like a night light if you wake up in the middle of the night.

To create a sense of intimacy and spalike luxury, consider installing a sculptural pendant lamp. Janey Butler, who runs Janey Butler Interiors, the interior design wing of the Llama Group in Cheshire, England, transformed a windowless bathroom into a dramatic space by hanging Ochre’s Celestial Pebble Chandelier over the tub.

“The light itself is a beautiful object that meets the eye on arrival to the room and provides focus to the free-standing bath,” Ms. Butler said. She also used LED strip lighting, concealed behind floating shelves, to wash the chevron-patterned floor with a subtle glow.

“When you have an empty and awkward corner, one trick of the trade is to transform that space with an oversized floor lamp,” said Caitlin Murray, the founder and chief executive of Black Lacquer Design, in Los Angeles. “Look for a lamp that is complementary in finish and material to the surrounding space, and an otherwise lost corner instantly becomes an intentional, polished part of the overall room design.”

To brighten up the space next to a desk in a bachelor’s living room, Ms. Murray chose the Detrick Floor Lamp, from Arteriors, in an earthy finish with a gray-green shade.

“It did the double duties of providing added light to his work space while also being a statement accent piece,” she said. “It was important to find something in tone and texture that both complemented the overall design and provided enough of a contrast to the surrounding neutrals to really make a visual impact.”

Don’t Overdo the Overheads

“Over the years, we’ve found that one of the biggest mistakes is made with overhead commercial lighting,” said Robert Highsmith, a principal at Workstead, the Brooklyn design firm he founded with his wife, Stefanie Brechbuehler, and fellow Rhode Island School of Design alum Ryan Mahoney almost a decade ago. “Often it can be excessive, generating spots and unwanted shadows.”

For that reason, Workstead advises residential clients not to use recessed overhead lighting. Instead, Mr. Highsmith recommends hanging a large pendant fixture or a chandelier in common areas. In the kitchen, he suggested using globe fixtures, “for even lighting” that leaves counter surfaces free. For living rooms, he said, try subtle lighting sources like wall sconces and floor lamps, and in dining rooms, “a sculptural centerpiece above a table provides depth, while accent lighting amplifies warmth.”