“Before“ photo of a room Lauri Ward has made over. (Redecorate.com/Use What You Have Interiors)

The cost of hourly fees and renovations can sometimes deter people from hiring an interior designer. And money isn’t the only reason.

As decorating has itself become a trend, giving rise to such networks as HGTV and loads of design blogs, it’s possible that more and more homeowners are developing an eye for design.

Or so they think. This is when Lauri Ward raises her hand.

“You wouldn’t believe how many people are embarrassed of their homes,” she said. “Even the DIY-ers get stuff wrong and end up back at square one.”

Ward, a self-described interior redecorator, founded Use What You Have Interiors in 1981. After graduating from the New York School of Interior Design in 1975, she found she was uncomfortable with the extent to which designers relied on sales to make money. So, she created a service-based firm where she’d charge a flat rate and help people redecorate their homes using the items they already had.

Lauri Ward (Redecorate.com/Use What You Have Interiors)

“The flat rate is key,” she said. “People like to know what they’re spending before I walk through the door, and I totally get that.”

Today, Ward has written four books and maintains offices in New York and Boca Raton, Fla. She also teaches hundreds of designers and aspiring redecorators her system, which equips them to work in any style, at any home and within any budget.

“It’s not just about moving furniture,” she said. “If we walk into an empty room, we’re ready to give the homeowners a full design plan complete with suggested furniture and accessories.”

A staple of Ward’s program is her list of the 10 most common decorating mistakes people make. Topping the list is the dreaded L-shaped conversation area.

“People love L shapes, and I can’t for the life of me understand why,” she said. “U shapes are the ideal. You shouldn’t have to put your knee up on the sofa to be able to face the person you’re talking to, and you should never have to put a wine glass on the ground. Always think U.”

Through three decades and thousands of clients, Ward said she has never seen a hopeless home. The end result might not always look professionally done, she said, but that is also the point.

“I like to think that I show people how to make their homes reflect them — but in their best light,” she said.

Ward will be teaching a day-long seminar at the Smithsonian Institution’s S. Dillon Ripley Center on Saturday from 10 a.m. to 3 p.m. Tickets are $120, $85 for Smithsonian members, $77 for seniors. For more information, call 202-633-3030 or visit Smithsonian Associates.