(Real Simple) -- Were Mom's fashion rules made to be broken? A panel of fashion designers style experts weighs in on what to wear, and what to leave in the past.
"When you have a choice between wearing pants or a skirt, carefully weigh your options...and choose the skirt."
Lloyd Boston, author of "Before You Put That On": Truer than ever. Why not go for the skirt? In this age of metrosexual men, sometimes the only thing that separates you from the guys is the power to put on a skirt.
Stacy London, cohost of "What Not to Wear" and a New York City-based style expert: Amen to that, Mom. It's much easier to find a skirt that's flattering. With pants, you have to consider the rise, the width of the hips, the legs, and how they fall on the tush.
Malia Mills, designer of Malia Mills Swimwear: Carefully weigh your options... and then choose what will make you stride into a room like you own it.
"Wear socks that match your pants."
Jenna Lyons, head women's designer for J.Crew: This is so outdated. It's better to give a nod to your pants. If you're wearing gray slacks, try argyle socks with a touch of gray in them.
Deborah Lloyd, co-president and creative director of Kate Spade New York: When it comes to socks, tights, and leggings, the new rule is there are no rules. Personal style is all about mixing it up and playing with color and texture.
Dana Buchman, designer: Who wears socks? It's hosiery or, better yet, nothing at all.
"Always wear shoes that are close in color to your pants, especially if you have big feet."
London: Wearing shoes that are exactly the same color as your pants is about as exciting as watching paint dry.
Buchman: Oh, my goodness. That really dates from 1910. With all that's going on with shoe design, doing that would leave you out of a lot of the excitement of getting dressed.
Lyons: That's crazy. There's nothing better than a bright shoe. As long as it doesn't make your foot look like a boat, you're fine.
"Ignore size -- go with what fits you and looks good. Don't get fixated on the numbers."
Boston: Moms who know this are geniuses. Remember: The tag is not on the outside of the garment, so no one is going to know. If it makes you feel better, cut the tag out.
Buchman: Bless this. It should be taught in schools.
Lloyd: This is great advice from a good mother. In a world filled with number-obsessed shoppers, we should keep in mind that clothes that fit properly just look better.
"Just because it looks good on the hanger doesn't mean it will look good on you."
London: Never judge an item of clothing on the hanger. Clothes are presented that way only because hangers make it easier to store them. You must try them on to know whether the clothes fit and look good on you.
Laura Bennett, designer, architect, and former "Project Runway" finalist: If a pencil skirt doesn't work with your body type, I don't care how many pencil skirts you see in stores -- just don't go there.
Buchman: I would tell everybody to try something on. It's all about the mirror, not the hanger. That's why there are dressing rooms.
"Never buy something on sale you wouldn't buy at full price."
Lyons: Brilliant! Everyone should live by that. It's ironic: The thrill in finding something cheap is that it feels like a deal that no one else is getting. But there's a reason no one else bought it―that's why it's still sitting there.
Buchman: Absolutely. Sometimes moms are so right. If you don't want it, you don't want it―period. It will just take up time and space.
Nanette Lepore, designer: Actually, a sale is a perfect time to try out a new trend.
"When you don't have time for a shower, pearls and ponytails are the next best thing."
Boston: Yes to the ponytail, even make it a chignon. But scratch the pearls and instead spray a little Febreeze on your outfit. Coming across as fresh is important.
Bennett: I live in a ponytail. But as for the pearls, they can make you look like a politician's wife if you're not careful. I like putting on a really long strand that makes a statement.
Mills: Pearls, a ponytail...and hot pink underwear. Never underestimate the power of a fabulous set of Skivvies.
"Buy quality, not quantity."
Boston: Good one, Mom! The woman who has one beautiful, quality tailored black suit can wear it a million times and still look better than the woman who has 17 different pastel suits with threads hanging out of the sleeves.
Mills: I prefer to see my closet as a well-mixed drink: two parts quality to one part quantity. I have $325 wedges sitting alongside $19 faux-lizard heels.
Lyons: Definitely. There's a reason why most of your favorite things are probably the ones that you splurged on. You can go back to them time and time again, and they'll still look great.
"Wearing all black should be reserved for funerals."
Boston: If that were the case, then the most stylish women in Manhattan would be one long funeral procession. Head-to-toe black is universally accepted as chic.
Bennett: Unless you're wearing a big hat with a net on it, all black isn't going to make you look like you're going to a funeral. It's a flattering uniform that can be worn every day.
Lyons: That is so dated. These days, even bridesmaids wear all black. Just remember that when you're wearing all black, you're creating a silhouette, so choose the shapes of your tops and bottoms carefully.
"If you can't breathe in it, you probably shouldn't leave in it."
London: Women have a tendency to squeeze into things and say, "If I buy this, there will be motivation for me to lose weight." Then, when that doesn't happen, the skirt hangs in the closet as a shameful reminder. Tugging at your clothes is never a good look.
Bennett: Good advice. Sometimes going up a size actually makes the fabric drape better. When something is pulling across the butt -- trust me -- that's what everyone notices.
Mills: Too tight is never right. Don't leave in it unless you can dance in it!
"Always wear a good bra -- it will make any outfit look better."
London: Keep the girls up and high! Take care of them and they'll take care of you.
Boston: Mom is 100 percent right. And you shouldn't be wearing the same bra in your 40s that you wore in your 20s. There is technology nowadays that can make women look trimmer, slimmer, and shapelier in an instant.
Lepore: Believe in that. You don't want your bosom hanging low. Different women have different needs -- but no matter what, if you have a bra you love, you'll feel and look better.
"Always wear a slip."
Boston: Absolutely not. A little mystery around the silhouette of a leg is not a bad thing. It's not like people don't know you have legs.
Buchman: Never wear a slip, unless you're 120 years old. And not even then. It adds bulk, it adds folds, and it looks tacky if it shows. Put that in the bank.
Lyons: Who wears a slip in this day and age? But women should take a good look at their undergarments and observe what they are doing to their backsides.
"Brown shoes? Wear a brown belt. Black shoes? Wear a black belt."
London: It may be kind of an antiquated rule, but it works. When it comes to shoes and belts, if you mix black and brown, it looks like you woke up and your lightbulb wasn't working.
Lyons: That is boring, boring, boring. Make your belt mean something to your outfit. It's not there just to hold your pants up. If you're wearing black shoes, put on a polka-dot or striped belt -- something with a little personality.
Boston: From a matching standpoint, it will never fail you. But it's better to mix up shades and finishes within the same color family, like cognac-colored heels in a faux-crocodile print with a cappuccino-colored ribbon belt.
"If you smile and make eye contact, no one will care -- or even notice -- what you are wearing."
Boston: No matter how big your smile and strong your eye contact, if you're wearing a bad blouse and a pair of pants that should have been donated to charity years ago, it's going to show.
Lyons: This is the most important rule. It is so much harder to be critical of what someone is wearing when she is lovely, connected, and interesting.
Lepore: That's easier said than done. Not everyone has this kind of confidence or personality, so don't dress like a clown.
"People can tell a lot about you by the shoes you're wearing."
Boston: Oh, yeah. Scuffed shoes, shoes with chewed-up heels, shoes that have never seen a shoe tree: They all say that you don't care as much as you should about life's overall details.
London: True. Shoes are a symbolic accessory -- much more so than jewelry or sunglasses.
Mills: Actually, people can tell more about you when they see how you treat a waitress.
"Always check your backside in the mirror before you head out."
Bennett: That's a good one. After all, your rear view is 50 percent of what people see. That's a large percentage!
Lyons: Absolutely. I wish more people did that. Women, check your panty lines.
Lloyd: Smart. Yes, I completely agree that it is wise to check what's going on back there. Everything that you care about showing or not showing from the front deserves the same amount of attention from the back.
"It's better to be overdressed than underdressed."
Bennett: No one has ever been asked to leave a party because of being overdressed. Everyone appreciates glamour.
Boston: I agree wholeheartedly. When you walk in underdressed, you have no wiggle room to change it. It's always easier to peel down if you are overdressed.
Buchman: It's better to look good than not. Dressing up or down is not the issue. When you're not sure how dressy an event is going to be, just wear the outfit you think you look best in.
"Don't mix high-end and low-end pieces."
Boston: Wrong. A serious $1,500 suit with a bright $5 tank top underneath it can look better than any other outfit in the room.
Lyons: I'm not a fan of this principle. Personal style could mean pairing sneakers with a ball gown. If that's what makes you different -- fine.
Mills: Ha! The more often you mix it up, the better. It's called style.
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