Costume Test Montage

Someone is trying to look good for something, a date, a meeting, long-lost relative, whatever. He decides he needs to wear something special, but what?

So the character goes through a dozen different costumes in front of the mirror. He or she will often try a funny one-liner matching the costume's persona, or just as often dismiss it with a quip, usually "too butch" or "too much" (in which case the next one is "too little"). Someone else might be giving out the running commentary.

The Shopping Montage and the Makeover Montage may do something similar, but those are still fundamentally shopping sprees and makeovers. See also Fashion Shop Fashion Show, which draws on the "models on the catwalk" presentation.

No real life examples, please; Real Life does not have montages.

Examples of Costume Test Montage include:

Anime and Manga

When Sebastian in Black Butler needs to infiltrate a building as Nina the tailor's assistant, Nina refuses to let him join unless he puts on something more fashionable. Unfortunately light colors are the current trend and so nothing looks particularly good on him, not even the anachronistic Elvis jacket.

Comic Books

One appears in Quantum and Woody when the titular duo are trying on costumes for their new crime-fighting identities.
Herr Starr from Preacher has a rather hilarious montage across two pages as he tries to find something to cover up his new "urethra scalp" scar, before settling on a Panama hat.
Used in Arana, with an array of other people's costumes altered just enough to not get sued, in the case of things like a Wonder Woman costume (with a spider instead of a W).
A flashback shows Deadpool trying on a variety of costumes at a local shop that caters to the superhero crowd. He eventually settles on a black and red number with a note attached saying something along the lines of, "Thanks, but not what I'm looking for. --Your Friendly neighborhood S.M."
Madman did this early in his ongoing series when he switched from his initial mini-series' costume (with a full-head cowl and a sewn-shut mouth) to his more iconic look, with amusing comments about them (one covered with multi-colored circles of various sizes earned a "Wonderbread? Wunderbar!").

Film

Au Pair
Robin Williams in Mrs. Doubtfire.
- And in Father's Day.
Tank Girl. After sneaking into a Liquid Silver dressing room, the heroine tries on a variety of outfits in an attempt at Dressing as the Enemy (nurse, dominatrix and one other). See the sequence here, starting at 9:20.
Educating Rita - In the film, not the book.
Four Weddings and a Funeral
Eva from Igor has one trying on different wigs.
The titular character in Larry the Cable Guy: Health Inspector does this, trying to find a proper disguise for his investigation.
Fatal Instinct. Ned Ravine takes his secretary Laura Lincolnberry to a store to buy her a gift and they both end up trying on clothes to the tune Brown Eyed Girl.
Xanadu. Sonny Malone takes Danny McGuire to the mall to get some new clothes and they have a long song and dance number in which Danny tries them on.
The 90s film Airborne, with Wiley trying on outfits for a date in front of his cousin to the tune of "I'm Too Sexy" by Right Said Fred.
While he doesn't actually wear any of the costumes he designs, Peter Parker goes through a costume desigining montage in the first Spider-Man movie.
Tough Guys (1986). Archie Long (Kirk Douglas) is invited to a disco by a much younger woman, who tells him to wear something "hot". As he's been in prison for the past thirty years he doesn't know what to wear, so Archie goes to a clothing store where the gay owner, watching from a monitor screen, makes Archie wear a series of outfits until he's satisfied.

Archie: Well? Am I hot?
Owner: You're positively on fire, darling!

How the Grinch Stole Christmas: The Grinch deciding what to wear for the Whobilation. "Stupid... ugly... out of DATE..."

Live-Action TV

Sabrina the Teenage Witch - opening theme.
Doctor Who started doing the costume montage with the Fourth Doctor, and even then the Fifth Doctor avoided it. It became standard from the Sixth Doctor onward. In the serial Destiny of the Daleks, Romana does this with bodies!
LazyTown - "LazyTown's New Superhero", Stephanie trying new superhero costumes, uncle's commentary
Friends - Rachel does this in "The One Where No One's Ready".
Top Gear, of all things, when Jeremy Clarkson is preparing to test the new Audi TT.
Lois and Clark - Clark in one episode is trying on different suits for a date. In a reference to The Mask, Clark simply spins at superspeed to change into them to Cuban music and once satisfied, he notes "Smokin'!" before he darts off.
- Not to mention the Superman costume test parade in the pilot episode, set to "I Need a Hero."
One episode of The Mighty Boosh starts out with Vince putting on an impromptu fashion show for Bollo, all trying to pick out which fashionable clothes to wear camping. He takes them all.
During the intro of one of MTV's Movie Award Shows, Jack Black spoofs the Peter Parker "Costume Design Montage" from the first Spider-Man movie.
- "Too Gay..." "Not Gay Enough..." "Just the Right Amount of Gay"
One scene in The Big Bang Theory's "The Pants Alternative" involved Penny helping Sheldon pick out a new suit for an awards banquet.
Buffy merely holds up outfits in front of herself before her first day at Sunnydale High—but her commentary is hilarious.
The 2015 pilot/first episode of Supergirl includes a sequence where Kara tries and rejects several different costumes before settling on a version of her iconic look, as informed by Man of Steel. For Bonus Points, the rejected costumes are all outfits her comic book counterpart has worn at one point or another during her history.

Music

Pink's music video for "Get the Party Started".

Newspaper Comics

Calvin and Hobbes - A Sunday strip had an "all funny sunglasses" variant. Because it was Calvin's POV, the panels were tinted the matching color and just showed Hobbes' reactions. We only see the pair he settles on in the end - which, in a case of Hilarious in Hindsight, look just like those of a certain mecha pilot.
Garfield uses this in a Sunday strip on April 17, 2011, with Jon trying on several clownish pants that he thinks he can wear for a date and Liz reacting to them sarcastically.

Web Comics

DMFA starting here, including copious amounts of Shout Outs. None to Harry Potter on explicit demand by Dan.
Legend of Bill starting here. Bonus points for every costume borrowed from other webcomics.
Wapsi Square once featured a sequence with Monica and Shelly trying on various Halloween costumes starting here.
Supernormal Step used one here with every costume being a Shout-Out
What's Normal Anyway had this sequence where Mel was deciding which transgender persona to dress like as an effort to impress his new friend.
Sun Wong in Rival Angels is subjected to one of these after her trainer tells her that she needs a gimmick and the attire to go with it. Look at it here, and decide whether you want to laugh, feel bad for her, or both.
Supernormal Step has lead character Fiona trying on a variety of costumes (all of which are references to other things) before settling on a black and blue Civvie Spandex outfit

Western Animation

Phineas and Ferb - Candace in "Flop Stars", Stacy's commentary.
- Also from the episode "Boyfriend From 27000 B.C.", where Candace tries to find a costume for Stacy's costume party.
Batman the Brave And The Bold - episode "Legends of the Dark Mite!" Done by Bat-Mite to Batman. Each of the costumes is some manner of Mythology Gag.
American Dad - Suitably, Roger has a Costume Test Montage. Having a loose Fourth Wall, Rodger gleefully announces the trope he's invoking.
Dexter's Laboratory - Dee Dee and her friends do this to Dexter after he crashes their slumber party in "A Tribe Called Girl".
The Simpsons - Episode "Bart the Lover"
Static Shock has a montage of Virgil trying to come up with a cool costume for his super-hero alter ego.
In the first episode of My Little Pony Friendship Is Magic, Rarity does one of these to Twilight Sparkle. "Too green! Too yellow! Too poofy! Not poofy enough!"
In the episode "Clothes Minded", Kim Possible tried a bunch of different outfits after her original mission duds got ruined. At one point, we see a montage of Kim trying various options, none of which meet Ron or Rufus' approval.
Joan of Arc suffers through no less than two makeover costume montages by Abe and Cleo respectively, and Gandhi gets one courtesy of Kennedy. (The winning outfit is of course an exact duplicate of JFK's clothes, plus wig.)
In the Tiny Toon Adventures short "Buster's Guide to Dating", Babs rejects her usual outfit and starts running in and out of her closet in different outfits. Finally, an animated animator's hand paints the scene yellow and Babs ends up in... her usual outfit! "Perfect! Thanks."
In one episode of Darkwing Duck, Drake Mallard does this when he is forced to abandon his Darkwing persona and tries to come up with a replacement super hero identity.
One episode of Doug has this, in which Doug is in a shop and tries to find an alternative to his Limited Wardrobe outfit.