Bridesmaids’ dresses have come a long way form the days of chartreuse satin and ruffled turquoise sleeves (a.k.a. the ’80s), but there’s still a lot of room for error. So what should you do when your cousin/sister/best-friend-since-birth asks you to wear a too-tight Pepto pink gown? Speak up! (Kindly).

Plan ahead

Don’t bring up bridesmaids’ dresses right away—the bride has a lot on her mind. Ask her tons of questions about her own dress, which will get her thinking about attire. Then say, “Whenever you’re ready to talk about bridesmaids’ dresses, just let me know if I can help with anything.” That’s it. You’ve started the ball rolling.

“When she does mention some possible bridesmaids’ dresses, make sure you act immediately,” says Sharon Naylor, author of The Bridesmaid Handbook (www.sharonnaylor.net). “Email your choices right away before the bride gets overwhelmed.” If you wait a week, she may not be as open to your suggestions.

As for the ideas themselves, New York City stylist Tanesha Smith says that a square-neckline, knee-length sleeveless dress with an A-line cut flatters most shapes. “It’s good for all manners of underpinnings and bras,” she explains, “and the A-line shape works for people with hip-and-thigh issues.” If anyone in the party is sensitive about her arms, suggest an optional shawl addition, advises Smith.

And the color? “A rosy-blush shade looks good on everyone,” says Smith. “It picks up on the natural flush of color we all have, regardless of our particular skin tone.”

Discuss Concerns

If the bride sends you three final picks and you don’t like any of them (The cut is going to make your butt look like a caboose? The color will render your skin a deathly hue? She’s chosen a terrible fabric for an outdoor wedding?), write directly to her about it, advises Naylor. “Don’t make the common mistake of emailing all the bridesmaids to sway them toward your choice. Brides don't like being ambushed with a different dress that you’ve all discussed behind her back.”

Go right to the top and consult with the bride; tell her exactly what you don't feel comfortable with, and suggest specific solutions, remembering to give positive feedback too. If she suggests a strapless dress and you need something to hold up your ample chest, tell her you love the color and then casually ask if you can add simple straps to your gown. If the fabric is the problem, say, “The cut is gorgeous! But since it’s going to be hot outside, maybe we can look for a lighter fabric so that we’re not all sweaty.”

Timing is Everything

Don’t call the bride too often about the dresses, warns Naylor. And just like you would with your boss at work, it's always a good idea to email her to ask when would be a good time for you two to talk about the gown selection. “Brides love it when you respect their time this way,” says Naylor. “And they’re more likely to hear you out in a real conversation than if you just sent a dozen links to dresses you like.”

Mission Failure?

If the bride ends up choosing a gown you hate—it’s too sexy, heavy, shiny, informal, unflattering on you—confirm that her decision is final by approaching her cautiously. “Ask her nicely if she’s still accepting suggestions from the group,” advises Naylor. If she says no, make sure to express your thanks and your excitement about the event (it’s not dishonest if you don’t focus on the dress in particular, right?). “Know that a good seamstress can work magic with any dress to alter it for a better fit on your body,” affirms Naylor. Sadly, you’re stuck with the color and fabric.