If there's one thing us women can agree on, it's that strapless bras are the devil. I think the concept itself is genius- wearing a tank top or tube top with your bra straps showing is just tacky. However, I find that strapless bras are more of a pain than helpful "support". For the past 10+ years that I've had boobs, I've gone through my fair share of strapless bras and I think I've finally found the magic secrets to finding one that gets the job done.
First off, you need to assess your cup size. If you are an A cup, you can probably get away with wearing the cute bandeau styles that are everywhere now. They'll give you enough coverage for most clothing and keep you comfortable. The fact that you can wear a comfortable strapless bra without cups and wires should make you thankful you have small boobs. Seriously- think about it! If you're in the B-range, you can get away with almost anything. I opt for a basic strapless bra with cups and just enough coverage. If you're this size, you need something more than a simple bandeau, but you can avoid anything too crazy. C and D-cups should focus on finding strapless bras that are made for larger cup sizes. You don't want anything that has too-much push-up to avoid looking too risque. You want something with a good amount of coverage and definitely a lot of support. If you are larger than a D, check out specialty stores made for larger cup sizes- they have so many options to choose from.
Next, make sure that the bra fits correctly in the band size. I know "experts" might warn you against this, but for strapless bras I always go down a band size so that the band is extra tight. This prevents the bra from slipping and falling down every 5 minutes. No one wants to be that girl in the wedding party photos who is constantly pulling up her strapless bra because it keeps falling down. Another fix for this is to take the bra to a tailor and have them sew in snaps/fasteners on the band. This provides a tighter fit (the opposite of taking a bra to the tailor and adding an extender to make the band longer).
Lastly, try on the bra with a shirt over it.So many women and girls just try on the bras and don't both to see what they look like underneath their clothing. I used to be guilty of this. I'd buy a bra only to get home and put a shirt on over it and realize it made my girls look pointy. Or that the lace accents on the bra totally showed through that white graduation dress. Oops. Strapless bras that have too much pushup will make the bottom half of your breast look flat, while the top part spills over- not a good look. Strapless bras that don't plunge down deep enough will become a problem with you try to wear that V-neck top. So save yourself money and embarrassment and try on the bra with a few shirts before purchasing. Shop similar styles here: