“Subtle, indirect fixtures, like table lamps, sconces and under-cabinet lighting, create ambience without taking over,“ said San Francisco designer Justin Colombik. Ms. Langdon forecasts a shift to softer, diffused light—through a lampshade or opaque glass—that provides a mellow, comforting glow, as does the Lutyens Lozenge Lantern at right. Ms. Gonzalez Touzet has installed perforated ceiling panels that create a naturalistic dappled light. Said Mr. Jayne, “We use uplights occasionally to add pockets of light and highlight architectural interest.”

OUT: Lacquer Lust

“It seems just about everyone has done a lacquered study or dressing room,” San Francisco designer Heather Hilliard observed. She recommended restricting paint with a high-gloss finish to features such as statement walls and built-ins, juxtaposed unexpectedly with textured walls. Brigitte Coleman, design director of New York interior decorating firm Pembrooke and Ives, also suggested mixing high-polish paint with earthy materials such as wood, or stone that has been leathered (that is, given an irregular finish).

IN: Vertical Texture

Designers are turning to more tactile walls clad in suede, linen and silk for a “rich environment with layers of character,” said Susan Clark, founder of online design retailer Radnor. Nashville’s Jonathan Savage suggested plaster on canvas or woven grass-cloth to add depth and dimension to a room. “Residentially, gallery-white is going away as people crave livable luxury,” explained New York designer Michael Tavano. He uses drapery or beaded wallpaper, like the Perles Wallpaper from Élitis at right, even behind framed art.

OUT: Hectic Ceramics

“Patterned tiles can come off as trendy and really dominate a space,” cautioned Nest Studio founder Jessica Davis. Long Island interior designer Allison Babcock specified that busy Moroccan tiles in particular “can’t stand the test of time in your kitchen the way a classic stone or ceramic subway tile can.” Los Angeles designer Nell Alano suggested using décor details (a stool, a lamp) with a Moroccan feel that are easy to change out in lieu of tile, “which is a big expense and production to replace.”

IN: Variegated Glazes

Ms. Davis uses solid-colored tiles with variation in glaze, which she said have a beautiful but subtler effect than patterns. “People are moving toward tiles that are special but not so loud,” said San Francisco designer Kristen Peña, who’s liking neutrals, ochers and greens, such as the Sea Foam tiles from Fireclay at right. And though inlaid Moroccan versions have fallen from favor, unpatterned zellige tiles still hold appeal. Raleigh, N.C., designers Zandy Gammons and Liles Dunnigan, meanwhile, favor tiles with a sophisticated antique patina.

OUT: Not-So-Heavy Metal

“Wire chairs are very specific to one particular style and feel too trendy—they box themselves in,” said Jessica McCarthy, creative director of Decorist. Also saying goodbye to that seat: Los Angeles interior designer Matthew Rosenberg. “The mass-produced wire-framed chair surged in popularity because of its modern, clean aesthetic,” he said, “but people are looking for more inviting, natural materials now.” Past their prime, too, are any vintage classics, like Saarinen and Eames pieces, said Mr. Colombik, unless you have originals. “Skip the reproductions.”

IN: Refreshing Rattan

New York designer Laurence Carr predicts a return of wicker used unexpectedly—“not just on your grandmother’s front porch in the summertime”—from accents to light fixtures to seating like this Butterfly Rattan Armchair, right, from 1stdibs. Mr. Rosenberg champions cane: “It’s a more organic option, providing the same geometric features that wire-frame chairs do but without the cold stiffness.” Ms. McCarthy likes cane’s versatility: “Natural-colored cane has a traditional feel while a bright blue painted rattan can feel very modern.”

OUT: Frayed Knots

“Nostalgic, boho macramé wall accents and oversize tie-dyed tapestries of the ’60s and ’70s saw a quick and tremendous revival,” Los Angeles designer Laura Muller said, “but they hit a saturation point in 2018.” Contorted rope, as it turns out, is once again passé. “I love celebrating artisans and their work, but having a hand-knotted wall hanging in one’s home feels very dated,” agreed Houston designer Brooke McGuyer. “Try hand-painted, framed Chinoiserie panels or an antique European hand-woven tapestry instead.”

IN: Big, Cheap Art

Fine art might be fetching record prices, but impressively scaled photos, prints and original pieces are more attainable than ever. The Jen Garrido giclée print, at right, from One Kings Lane, runs $399 for a framed 3-feet-by-4-feet version. Portland designer Max Humphrey finds sizable works at Minted, Society6 and Eventide Collective. New York designer Caleb Anderson cites West Elm, CB2, website Saatchi Art, and scores student art on Etsy . He recommends custom frames to elevate the art. “Even inexpensive ones are better than store-bought.”

Corrections & Amplifications

Matthew Rosenberg, founder of Los Angeles firm M-Rad, is an interior designer. An earlier version of this story identified him as an architect. (January 3, 2019)