Before and after shots of Robb Tennant

Robb Tennant, 29, with girlfriend Jacqueline Nicholls

Before: Too much facial hair is one of Undateable's main deal breakers. But for Robb, a musician with the alternative-folk band Rooftops, not shaving was a symbol of mourning based on Jewish ritual: His mother died five years ago, and he found it tough to move on. Robb's teenage clothes also needed to evolve. "I'd like him to look more clean-cut and sophisticated," says girlfriend Jacqueline, a fashion designer.

After: "From Amish farmer to Robert Redford!" raves Anne Coyle, coauthor of Undateable. The suit is slightly rumpled, so he looks hip, not stiff, and his shoes are worn sockless. Contacted a month after his transformation, Robb reports a "92 percent positive response" to his absent beard (just like a guy to quantify): "I expected teasing and jabbing, but people are surprisingly supportive."

Suit, J.Crew, $366. Shoes, Florsheim by Duckie Brown. Shirt, Brooks Brothers, $80. Tie, Ralph Lauren Purple Label, $135. On Jacqueline: Dress, Kate Spade New York, $395. Earrings, Helen Ficalora. Bracelets, House of Lavande, CC Skye. Shoes, Stuart Weitzman.

Before and after shots of Max Smith

Max Smith, 32, with friend Tessa Jean

Before: "I got into a rut," confesses Max, a paralegal. More like a mire—witness the boxy, too-big polyester suit, deplorable tie, and overly sculpted facial hair, including soul patch. "I tell him, 'Max, you're Ivy League material. Play the role!'" says Tessa, a nurse who is Max's best friend and style adviser.

After: "He has a sense of pride that was missing before," says Anne. In a perfectly cut pearl gray suit, Max projects the authority he needs for court appearances, yet he doesn't come off as too conservative: There's wit to the mix of striped shirt and polka-dot tie. "Oh my gosh, he looks amazing!" Tessa cries. "I knew he could rock it!"

Suit, Phineas Cole. Shirt, Brioni, $595. Tie, Ermenegildo Zegna, $170. Shoes, John Lobb. On Tessa: Jacket, Madeline Weinrib. Blouse, Kate Spade New York, $195. Jeans, Prvcy Premium, $194. Necklace, Stephen Dweck. Green pyramid ring, Kara by Kara Ross. Ivory ring, House of Lavande. Shoes, Christian Louboutin.

Before and after shots of Leif Erik Vik

Leif Erik Vik, 45, with girlfriend Susie Earls

Before: Baggy. Light-wash. Worn waist-high...these are just some of the denim felonies committed by custom builder Leif. He dresses as if he lives on a construction site—which is where he met his girlfriend, Susie, an interior designer. "He has this wonderful rustic appeal, but he owns way too many 'cozy' clothes," she says. "He needs a more diversified wardrobe."

After: "He looks fantastic, like an Italian aristocrat!" says Anne. Less facial hair—less hair in general—reveals Leif's gorgeous face and innate elegance. But he's still rough-hewn enough that the red pants and yachtsman's blazer don't seem too country club. "I'd wear this for an event," he says. "If I walked into the lumberyard, the guys would go, 'Whaaat?'"

Blazer, Polo Ralph Lauren, $1,195. Shirt, Ermenegildo Zegna, $325. Pants, Jay Kos, $295. Pocket square, Boss Black, $30. On Susie: Jumpsuit, Luca Luca. Earrings, Cara Croninger. Cuff, Aurum Vitae by Tam Tran. Ring, Coomi. Shoes, Bally.

Before and after shots of James Taylor

James Taylor, 64, with daughter Leia Taylor Ward

Before: A former homicide detective, James used to go to work in custom-made suits. But since retiring ten years ago, he admits, "Maybe I've fallen back in that area." Daughter Leia is blunter: "I ask him, 'Dad, did you get dressed in the dark today?'" Among her gripes: bulky pleated pants, a tucked-in sweater, a baseball cap, and a cell phone holster where he once carried his gun.

After: A refined version of the casual comfort James likes—light-colored, well-fitting clothes—show off his excellent physique ("I can do 100 push-ups in five minutes"). And he's lost the droopy mustache. "He looks like a million bucks!" Leia says. "Now he has to toss his old wardrobe and go shopping."

Sweater, Christopher Fischer, $1,175. Pants, Isaia, $425. Belt, Maison Martin Margiela. Watch, Hamilton. Shoes, Tommy Hilfiger. On Leia: Dress, Elie Tahari, $448. Earrings, Janna Conner Designs. Necklace and ring, Kara by Kara Ross. Cuff, Tory Burch. Belt, Hobo International. Shoes, Christian Louboutin.

Before and after shots of Frank Coleman

Frank Coleman, 50, with wife Bambi Everson

Before: "He is the kindest man on the planet, yet he terrifies young children at first glance," says Bambi of her husband and third-grade sweetheart (they reunited online after 35 years), Frank, a punk-rock drummer with the bands the Bentmen and the Dead Ramones. Maybe it's the "skullet" (bald head plus long hair), or the monster-movie tee, or the grubby black jeans. "I shop only at gunpoint," says Frank.

After: Rebel without flaws! "It shows confidence to go completely bald—there's nothing sexier," says Ellen. And now that Frank's beautiful blue eyes stand out, Bambi hopes his gentle soul will also be more apparent. Wardrobe elements are similar to his former daily uniform, but softened: a shawl cardigan; French fisherman's top; dark-wash jeans.

Cardigan, Gap, $70. Top, Saint James, $65. Jeans, A.P.C., $165. Sunglasses, ICU Eyewear. Boots, The Frye Company. On Bambi: Dress, L.L. Bean Signature, $79. Silver bangle, Robert Lee Morris. Wood bangle, R.J. Graziano. Ring, Kara by Kara Ross.

Before and after shots of Joel Duek

Joel Duek, 41, with wife Gaby

Before: Paging John Travolta in Saturday Night Fever! Ellen and Anne singled out composer Joel for his shiny shirt and pants, anomalous vest and glut of rings and necklaces: "The only acceptable man jewelry is a watch and wedding ring, signet ring, or Superbowl ring—if you were on the team," says Ellen.

After: This guy dazzled us with his adorable looks once he switched to gimmick-free clothes—a button-down shirt, V-neck sweater, khaki pants and all-weather coat. Although Joel feels "sanitized" without his usual jewelry, both he and his wife Gaby, who works at the United Nations, are thrilled with the haircut. He also found it liberating to explore a lighter, less melancholy palette: "It's opened my eyes to the existence of color."

Shirt, Brunello Cucinelli, $430; 212-813-0900. Sweater, Brooks Brothers, $348; Pants, Burberry, $250; 800-284-8480. Coat, Valentino, $1,395; 212-772-6969. Belt, Burberry. $225; similar styles available at Shoes, Ermenegildo Zegna, $495; 888-880-3462. On Gaby: Dress, Adam, $395; 212-229-2838. Necklace, J. Mendel, $695; 212-832-5830. Bracelet, R.J. Graziano, $75; 212-685-1248. Ring, Ippolita, $225; Belt, Lai, $350; 212-794-3874. Shoes, Coye Nokes, $585;

What every man should have in his closet