InStyle’s Fashion Director Cindy Weber Cleary has been a fashion editor for the past 20+ years. Needless to say, she’s picked up some tricks along the way. Catch her column here each week for how-to tips and style secrets on her favorite, timeless styles.

In the summer as I am going to and from work, I like to play a little game. I look at all the women rushing by on the sidewalk and I try to guess where they work, based on what they are wearing. Sometimes it’s obvious. Anyone in a suit and pantyhose with closed toe pumps on a sweltering July day must surely work in a very conservative environment such as a bank or law office. Otherwise, no one would choose to dress that way in such heat. But, in recent years, it has become much harder to guess about the rest.

I don’t know when it became common for young women to wear strapless cotton jersey maxi dresses and flip-flops to the office, but I see plenty of them these days. Women of all ages make bra mistakes, such as wearing a regular bra with an open-back dress or racerback top. I recently saw a middle-aged woman in my building wearing a paisley chiffon poncho with Lycra bike shorts! And it wasn’t even a “casual Friday”!

Here’s a simple rule of thumb about getting dressed on hot days: if you could wear it to the beach or the gym, you probably shouldn’t wear it to the office.

No matter what your age, it’s important to keep in mind that the bar for dressing professionally doesn’t drop just because the temperature rises. So here are some simple tips for staying stylish and comfortable.

Dresses: Loose, tunic-like dresses or shifts are generally more comfortable than fitted styles, but proportion is key. These look best if they hit just at the top of the knee or a few inches higher, depending on your age and your comfort in showing your legs. If you are self-conscious about wearing a sleeveless dress, toss a light cotton jacket or cardigan over your shoulders. A fit-and-flare shirtdress in cotton or silk is another great, easy-to-wear choice.

Courtesy

Get the look (from left): Trademark, $162, trade-mark.com; Tibi, $575, tibi.com; 3.1 Phillip Lim, $550, net-a-porter.com.

Shirting: I love a crisp cotton or soft chambray shirt paired with a pencil skirt, an A-line skirt, or a cropped pant in a structured fabric.

Courtesy

Get the look (from left): Reiss, $145, reiss.com; J.Crew, $98, jcrew.com; H&M, $20, hm.com.

T-shirts: I occasionally wear a T-shirt to work on an especially humid day, but I am always careful to choose a high quality cotton or a cotton/linen blend in a fitted shape and pair it with something dressier, such as a silk full skirt or a slouchy trouser and a heel.

Courtesy

Get the look (from left): J.Crew, $25, jcrew.com; Vince, $120, farfetch.com; Clu, $175, net-a-porter.com.

Accessories: Your shoe and bag are key if your clothing is slightly more casual. A structured bag or sleek pump can elevate the simplest look and show that you mean business.

Courtesy

Get the look (from left): Coach, $245; coach.com; Kate Spade, $398, katespade.com; Club Monaco, $269, clubmonaco.com.

Finally, as for lingerie, invest in a convertible bra that can be worn with different necklines. Your bra should never be visible in the workplace. And don’t give up on shape wear just because it’s hot. Spanx makes a great light-weight shaper in a breathable fabric (spanx.com).

For more work wear ideas, click through the gallery to see celebrity-inspired summer outfits to wear to work.