Office dress codes are getting more and more casual - but there are 5 things you can never get away with

When wearing jeans to work, Gallo said you should only wear your nicest pairs. That means no stains, no signs of fading, and, most importantly, no rips or holes.

If any part of your leg is exposed when wearing the pair of jeans, don’t wear them to work.

Opt for jeans with a dark wash. Dark-wash jeans look more put-together than light- and acid-wash jeans. As a light-wash enthusiast, this is one of the best pieces of advice I've received.

Gallo said that modeling your work clothes after what your boss wears is key to mastering a casual dress code.

“You want to dress for the job you want, not the one you have,” Gallo said. “I would use my boss as a guide for what I should be wearing. If they are more business casual, then I would follow suit. If they are very casual, then you have an open door to dress that way.”

At a previous job, I learned that it generally isn't OK to wear your college sweatshirt to work, even if it's a summer Friday.

No one in your office cares where you studied, nor is it relevant now. Unless you are working for your university, you should leave your comfy college apparel at home. Save your cozy college hoodie for a nice nap after a long day at work!

No matter how casual your office is, or how rushed you are in the morning, make sure you take the time to pull yourself together.

“You just don’t want to look unkempt,” Gallo said. “I believe that what you wear is a reflection of you who are — if you are wearing clothes that are wrinkled, ratty, or dirty, then you are saying something about yourself.”