Claire Asher is a the fashion product director at Boohoo, a fashion website known for affordable, trendy styles spanning the categories of clothing, shoes and accessories.

I first tapped fashion pro Asher for her expert advice as far as which types of styles one should look for when shopping for a black tie dress code. Her advice pretty much boils down to something that's classy, comfortable and, preferably, floor-length—though as you'll soon see, there is a little wiggle room. (You can read some more of her suggestions at the bottom of this article.) I then asked fellow PureWow editors to share the dresses they've worn over and over to these types of events in the past, and used their recommendations to whittle down this list. Finally, I looked into best sellers at some of my (and PureWow readers') favorite retailers to select highly rated numbers that are likely to stay in style—and good shape—for many wedding seasons to come.

Opt for a formal look that's in line with the theme of the event. "Guests to a black tie wedding should always opt for floor-length gowns, and if that's not your style, you can go for a slightly shorter midi-length dress or even a classy suit," says Asher. Don't feel beholden to just a few styles, as there are a lot of options out there, whether you prefer to dress up a simple gown with jewelry and extravagant heels, or you want to go with a fun pick with fewer accessories. "Experiment with [a few different silhouettes] to see which [ones work for] your body type and which ones you find the most comfortable and can [move] in," says Asher.

If you need some help narrowing down your options, many retailers have a formal dress section, or even a black tie specific section to browse.

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