Ask an expert: Style questions answered on white pants, nail polish

Q: The truth about white pants … when can we wear them?

A: Scientists have proved that there is no time period during which the wearing of white pants will cause you to burst into flames. In fact, white has become such a trendy color that fashion mavens wear it year-round without giving calendar-based etiquette a single thought. However, I'm of the opinion that long-standing style rules like this should be followed if they feel important to you.

Traditionally, white pants, jeans and shorts have been reserved for summer wear — Memorial Day to Labor Day — and if you'd prefer to confine their wearing to that time period, do so. Winter whites like ivory and cream have long been worn in winter — think Thanksgiving to St. Pat's — and are generally shelved for fall. In fact, spring and fall are considered to be taboo times for white bottoms by the Old Guard.

At this point, if you decide to bust out your bright white jeans on a cold February day, the Fashion Police won't haul you away. But if donning white bottoms in spring or winter makes you feel like a sartorial sore thumb, forget it. Remember, all style rules are merely guidelines, made to be bent and broken as you see fit.

Q: I like wearing different colors on my finger and toe nails. For example, on my fingers I might have gray, on my toes silver. Or even more mixing up than that. What's your take?

A: Oh my goodness, go for it! In fact, it's currently considered far more stylish to wear one color on your fingers and a complementary but different color on your toes. Matched colors are out, harmonious colors are in. If, like me, you break out in hives at the prospect of picking two colors that both work with each other and with whatever outfit you happen to be wearing, stick to neutrals. For summer, light grays, subtle metallics and colors that are nude to your skin tone are all great families to sample. Pick one shade for hands, a slightly darker shade for feet.

Q: These people on TV do their concealer so well. No matter what brand I buy, I have circles under my eyes. What's the trick? Do I need a prep underneath or a powder on top? — Anonymous

First, before you apply any colored products whatsoever, moisturize the under-eye area. Be sure to use a product that's designed for this sensitive spot and use a tiny amount. This will plump up the skin, which means fewer fine lines for your products to settle into. Next, consider a color corrector, especially if you have noticeably dark circles. I use Bobbi Brown Corrector in Peach Bisque, which looks far too salmon-y for my pale skin but works miracles when applied. (Consult an expert to get your color right.) Then make certain you're using a concealer that is designed for the under-eye area. The skin here is thin and delicate, so concealers that work beautifully on chin zits will just clump and clog. Consider applying with a brush instead of fingers if your concealer of choice still accumulates in your fine lines.

And finally, if you use a powder to set your concealer, make sure it is extremely fine. Finer than anything you'd use to counteract shine in your T-zone. I've heard varying opinions from makeup artists about whether powder is beneficial or counterproductive for the under-eye area, so you could also consider skipping it altogether.

Q: Which trends are no longer trends? Example: should I get rid of my gaucho pants?

A: Remember the days when you had a window of about three weeks to obtain, wear and discard a trendy item? I do. And I'm so glad those days have passed. Trends have a much longer shelf-life now, and if you're creative about how you remix your trendy pieces you can wear them (almost) indefinitely.

That said, a few trends that you might consider shelving include wedge sneakers, embellished shirt collars, floral pants and jeans, bubble necklaces and cold-shoulder tops. Peplums, ombre and over-the-top neon are losing steam, too. Your gaucho pants are a tough call. Culottes are trendy now and gauchos are a close cousin. But to get the look right you need a pair made from a formal material like silk or twill, so if you're talking black knit foldover-waistband gauchos? Might be time to retire them.