Yale grad students approaching fall interview season hope to be dressed to impress, but potential sartorial snafus abound. Should they dress for the job they have or the job they want? Wear nude tights or show leg? And really, how short is too short?

They need not despair — not while Mary Anne Lewis GRD ’14, a Yale Career Services fellow, is policing the streets of the Elm City, cracking down on workwear faux pas. Her uniform? A fluttery blue silk frock and black high-heeled booties (this unabashedly preppy WEEKEND blogger needs no invitation to raid her closet).

Lewis organized a crash course in professional dress at two Chapel Street retailers, Tracy b. and Raggs, last Thursday night, giving the 25 grad students in attendance tips on Style 101 as they sipped white wine and noshed on red velvet cupcakes.

Your WEEKEND blogger was on the scene — and in a sharply observant mood.The crowd inside Tracy b. could have composed a hit-or-miss spread in a celebrity tabloid. Drawn by Yale-only discounts, campus fashionistas clad in BCBG and Parisian labels rummaged through the racks for stylish steals alongside their less sartorially-inclined peers, such as one who told me she was “stymied” by the concept of a collared button-down shirt. She clutched her neck as she spoke, mimicking the suffocating effect of a starchy blouse.

She was not alone in her confusion. Even a Yale post-postdoc would be daunted by the task of transforming the most confused of those seeking Lewis’ advice. They owned orthopedic shoes, ill-fitting suit jackets roomy enough for two and shudder cable-knit twinsets. The mere mention of the term “business casual” might plunge them into a panic.

“I mean, can you or can’t you wear jeans?” asked Michael Giannetto GRD ’16, as he emerged from the dressing room of Raggs, dapper in a crisp black suit and shined leather shoes.

It was a job for a professional — and Tracy Bonosconi, owner of Tracy b., stepped up to the plate. She laid down some indisputable ground rules: just say no to “hospital” green and “Halloween” orange.

I subtly loosened the scarf draped around my neck, which so happened to be said shade of pumpkin. Quelle horreur — I was one of them? The sales associate looked me up and down. “I like your glasses,” she said of my oversized cheetah-print frames, as if they were the single redeeming quality of my outfit, a lonely cry for help. She kindly insisted that I sign up for their raffle, even though I wasn’t a grad student. Regardless, it seemed that my case was desperate that I could use an all-expense-paid wardrobe makeover a la TLC’s “What Not to Wear.”

The sales associates gushed about Katharine Hepburn, little-known designers and the merits of cufflinks, tossing around terms like “statement pieces,” “minimalism” and “wearability” (is that a word?). It’s a parlance particular to commercial retail. I am by no means fluent, though I have watched enough seasons of “Project Runway” to place into at least L3.

But while it’s easy to follow those by-the-book maxims, store owners said the best professional wardrobes reflect personal style. Lewis told me her favorite workwear items are ankle-length cigarette slacks paired with a unique heel. Alark Saxena GRD ’13 has a penchant for pop-color ties. Kristin Graves GRD ’14 likes vintage items, but calls herself “a bit of a brand whore.”

Perhaps some things can’t be taught.