FORTUNE — Few in Silicon Valley know how to pull off a party like Susan MacTavish Best, praise that applies even on a slightly “off” night.

Best is throwing together a small, impromptu dinner in her San Francisco home, a 1,665 square-foot Victorian rental she stays at when she’s not at her New York City loft. The decor is warm, downright bohemian: beakers for cocktail glasses, some 200-year-old silverware and china, and a hodgepodge of mid-20th century, retro-chic (think Eames lounge chair) furniture juxtaposed by even older items, animal furs, and shag rugs. “You burned the steak!” the 40-year-old entrepreneur laughs from the kitchen. Her roommate, a 21-year-old founder CEO from Anchorage, Alaska, serves several slices of charred meat. Best comes to the rescue: “Here, this should help,” she says as she wrenches a jar of homemade verde salsa from her kitchen cupboard and sets it alongside the entree.

Surprisingly, it does. So do the endless refills of dry, sparkling pink wine sold at $14 a bottle that Best buys by the case and the racy chatter by her candlelit fireplace, yo-yoing from love lives to vaporizing marijuana pens. In other words, what seemed like a potential disaster is anything but. That’s par for the course for Best, an Oxford-educated, Scotland-bred press rep who built her professional reputation running Best Public Relations with past and present clients like Craigslist, Founders Fund, social scoring startup Klout, and Lulu, a print on-demand bookstore.

Cocktails from one of Best’s “Burns Night,” an homage to Scottish poet Robert Burns this January. Photo: Myleen Hollero/Living MacTavish

But in recent years, Best has made a reputation for throwing some of the hippest get-togethers in the Valley, down to that punch bowl filled with homemade whisky jello. Her themed, lavish soirees emphasize good taste and a curated crowd over Martha Stewart’s fetishistic quest for perfection, drawing folks such as retired U.S. Army General Wesley Clark, Webby Awards founder Tiffany Shlain, Pete Worden, director of NASA’s Ames Research Center, as well as employees from companies like Facebook FB , Google GOOG , and Pinterest. In 2011, she switched gears to focus on building her own company called Living MacTavish, bootstrapped with “hundreds of thousands” earned by her PR firm. Her mission: create an all-encompassing lifestyle brand not unlike Martha Stewart, but well, more accessible.

“Martha Stewart terrifies me!” Best says, sipping wine and giggling. “She talks about her perfections. God, I wish I had enough fridge space. I am the biggest slob. Things always spill in the wrong place. Sometimes I burn stuff.” Yet if the two entrepreneurs share common ground, it’s that Best wants what Stewart took decades to meticulously craft.

To be sure, there are other entrepreneurs attempting what Best is out for, albeit differently and to different degrees. Ex-Googler Brit Morin, and wife of Path CEO Dave Morin, has her Do-It-Yourself brand, Brit + Co. Others like Nicole Shariat Farb, a former Goldman Sachs VP, launched her DIY crafting kit startup Darby Smart last summer. But where many “makers” aim for down-to-earth accessibility, Best hopes folks will also want a bit of her lifestyle to rub off on them, too.

To wit, Best’s San Francisco home is a 24/7 shopping showcase. Many of the items in her home have price tags for a reason: Should a partygoer envy a particular chair, couch, or flute glass, they can buy it that same night. Last October, she shipped off many of the items in her San Francisco home via 18-wheeler rig and recreated the space in a 1,500-square foot space next to her New York loft so passersby could get a taste of the Living MacTavish experience. Oh, and those beakers Best is drinking from tonight? There are more down in her basement for sale.

If Best succeeds — a big “if” by any measure — it will be because of her tastemaking skills and ability to disarm even the most awkward. “What makes her unique is that she is so comfortable in her skin it doesn’t matter who she’s talking to, from Mark Zuckerberg to a valet,” says Clinton Fein, a South African writer and activist. “She’s just a very consistent, empathetic kind of person.” Worden earnestly agrees. “Within a few minutes, you feel like you’ve known her forever. The only other person I knew who was good at doing that was Bill Clinton.” 

Party or not, that’s good company to be in.

Musician Robert Reid Gillies performing at Best’s “Burns Night.” Photo: Myleen Holler/Living MacTavish