Most dresses get worn once and forgotten, but a prom dress gets preserved. It is photographed for hours, worn all evening, and then kept in a closet for years as a record of who you were that night. The prom dresses in this first group are all gowns that commit to a mood: Rachel Gilbert's off-shoulder velvet Ryn, Maticevski's draped satin Glow Up, the plisse chiffon halter from Silvia Tcherassi. None of them chase a passing look, which is exactly why they will still make sense in a photo album at thirty. Choose the version of dramatic that feels like your own taste, not the one that looked right on the hanger. Alexis's red-orange Calysea and the Paris Georgia Kate velvet add two more bold moods to the group.

The biggest mistake with prom dresses is choosing too much dress, something so embellished or so dramatic that it wears you instead of the other way around. A column or a clean a-line works when it follows your actual shape, which is why the Alex Perry draped column and the Rachel Gilbert Oryx read sophisticated on a range of bodies. Color matters as much as cut: if jewel tones suit you, do not default to pastel because it reads younger, and if pastels suit you, the soft ruffles of the Aje Canyon or the LoveShackFancy lace are a far better bet than forcing something dark. Choose the shape that makes you look like yourself, not the one that photographs loudest. If you want an easy place to start, the Significant Other floral maxi in this group is the simplest of the lot, and the Staud Jill is the one true A-line.

A prom dress gets worn for hours and preserved for years, so construction matters more here than in almost any other dress you will buy. The hem should be finished precisely, since a crooked or fraying hem is the first thing every photo shows. Look closely at how a piece like the Ulla Johnson Atrani is tiered and gathered, or how the Proenza Schouler Paulina pleats hold their shape, because that is where good prom dresses separate from the rest. A strapless line, like the Greta Constantine Stravinsky, needs real internal structure to stay put through a night of dancing. Good construction is the part nobody compliments and everybody eventually notices.

Comfort matters more than anything else, because the most beautiful dress is the wrong dress if you spend six hours miserable in it. Rigid fabrics look striking but rarely move with you, while a jersey or wool piece, like the Christopher Esber Suspended Jersey or the Diotima Origami, lets you actually dance. Fit matters just as much: sit in it, walk in it, and think honestly about whether you can get through the night in it before it is yours. Soft silks such as the DEME Talia or the Temily Parachute dress tend to hold their shape through hours of wear better than something stiff. The dress that survives the evening is the one you look back on with pleasure.

A prom dress is one of the few clothing decisions that gets photographed obsessively and kept for decades, so it deserves more thought than most party dresses. I would rather see someone in a simpler silhouette that actually fits their body than in a dramatic gown chosen because it looked exciting on a rack. Comfort and construction are not boring considerations here, they are the difference between loving the photos later and being unable to look at them. Fit the shoulders and the bodice before anything else, because no amount of embellishment fixes a dress that does not sit right. A decade from now, the one you will still like is the one that looked like you.