Whether you’re sporting designer labels or discount-chic, VPLs (visible panty lines, gasp!) and misbehaving bra straps can ruin any look. "They’re not only unflattering and uncomfortable to wear, but visually obvious to everyone around you," says Amy Czettisch, a lingerie fit consultant from Toronto. Avoiding such fashion disasters is easy: you just need to know what to put on under there. According to Czettisch, "Proper undergarments are complimentary to your figure whether your goal is to enhance, smooth or hold your assets." Here she shares her dos and don’ts for four of the most challenging offenders in your closet.

Challenging clothing item #1: High-waisted pencil skirt. This fitted skirt style can look über-sexy when done right – but without a little help, bumps and bulges are on full display.

Celebs that have pulled it off: Victoria Beckham, Gwen Stefani

Do: Wear a high-waisted body slimmer with thong back or "legs" to create a smooth line from torso to knee, recommends Czettisch.

Don’t: A proper fit is crucial, think snug but not sausage casing tight. Anything that will dig into your sides will create an indentation at the hips and a line across your stomach. This is not the time for low-cut bikini panties.

Slip it on: La Senza Mid-Waist Bike short, $26.50,
, or Silks Shaper Power Band Short-Firm Control, $30, www.phantom.ca.

Challenging clothing item #2:
Slim, white jeans. It’s all about bright, white denim this spring, so how do you maintain a bootylicious backside?

Celebs that have pulled it off: Sienna Miller, Kate Moss

Do: A seamless thong or g-string are the most undetectable. However, a microfiber boy short can also work as long as it lies smooth against your body and doesn’t ride up. With either style, choose a colour close in tone to your skin be it peach, beige or chocolate.

Don’t: Stay away from anything that’s white, "white underwear beneath white clothing is a definite no-no because all you can see is the outline of your underwear!" Czettisch warns. Similarly, stay away from lacy patterns and bow details that might stick out.

Slip it on: Calvin Klein microfiber extreme low-rise thong, $15,
or GapBody low-rise seamless nylon hipster, $12.50,

Low-cut camis and wrap dresses on the next page

Challenging clothing item #3: Low-cut, spaghetti-strap camisole. A little bit of cleavage is a good thing, but a bad bra can steal attention away from the girls.

Celebs that have pulled it off: Nicky Hilton, Penelope Cruz (in

Do: Invest in a good strapless bra. "The fit should be snug under the bust along the rib cage," says Czettisch, "giving your bust a ‘shelf’ to sit on without the bra sliding down your torso." She is also a big fan of professional bra fittings: "They’re the best source for a proper-fitting strapless bra if you’re over a C cup — and there are great options out there for D-cups too!"

Don’t: Show straps from a ratty, old bra. If you must flash them, make sure they’re pretty to look at, discreet and match, or at the very least co-ordinate, with the top. This is one fashion instance where black does
not go with everything.

Slip it on: GapBody sleek nylon convertible bra, $38,
or Calvin Klein Perfectly Fit strapless bra, $48, www.cku.com.

Challenging clothing item #4: Jersey wrap dress. This classic can be completely feminine and flattering or horribly un-forgiving, showing off every nook and cranny.

Celebs that have pulled it off: Kelly Ripa, Jessica Biel

Do: Try a body-contouring garment to smooth out everything. You can opt for a full slip style or a bodysuit with under wire bra for more support. For lighter coverage, Czettisch suggests a seamless, microfiber bra and brief.

Don’t: Ditch anything that digs into your skin that includes pantyhose, warns Czettisch. If you must wear hosiery make sure it’s high-waisted, the right size and has control top to smooth your hips and waist.

Slip it on: Silks Shaper Full Slip Tamer — Firm Control, $45, www.phantom.ca, or La Senza strapless dress, $34.50, www.lasenza.com.