Grouping objects in a pleasing arrangement is the goal of a vignette. Designers work hard on their tablescaping game, creating small compositions layered with texture and color that draw raves on Instagram. We asked some local designers to describe their process.

Susan Nelson and Todd Martz of Home on Cameron in Alexandria, Va. styled this mantel in a family room at the 2017 DC Design House in Potomac, Md. The bold wallpaper called for a simple object to hang above the fireplace; the accessories were chosen for their child-like qualities. (John McDonnell/The Washington Post)

"If you're lucky enough to have a fireplace, congratulations," says designer Susan Nelson of Home on Cameron in Alexandria. "They add instant warmth, character and are a focal point in any room."

Styling your own mantel is highly personal. Nelson and Todd Martz, who together designed the family room at the 2017 DC Design House, say it's important to consider the room's scale and the fireplace size as you experiment with art, mirrors, textiles or architectural elements above the mantel. For the shelf composition, you can go for a symmetrical arrangement with "a tall item on either side and a long, low something in the middle," says Nelson, which creates a fairly formal look. A more relaxed asymmetrical arrangement uses an odd number of things of varying heights. There's no formula. It's created by trial and error until the mix of heights, widths and colors looks right.

Their mantel had to stand out from their wallpaper, bold in both pattern and color: China Seas Sigourney in mustard. Because there was so much going on in the background, they hung a simple white carved wood mirror over the fireplace. They chose items with a childlike feel and a bit of whimsy. They put two tall floral sculptures on the left, as well as a small stack of antique books that belong to Martz with a tiny ceramic goose that belongs to Nelson placed on top. On the right is a 19th-century salesman's miniature chest, a handmade and child-size element.