Please give your feedback on each item. What do you think is most important? What do you feel is most important to employers?

18. Use your inside voice

Some individuals have loud, booming voices that demand to be heard. Sometimes, we get excited in conversation and forget about our inside voices. Either way, it is important to keep sound volume to a decent level. A loud environment distracts and disturbs others.

Plus, your office may share a building with several other businesses. They may be holding meetings or trying to work quietly. Be a good neighbor and use your inside voice.

19. Be aware of nonverbal cues

You might be surprised by how much your facial expressions, body language and hand movements convey to others. Your facial expressions play a huge role in how others perceive you.

For example, a recent study by Cornell researchers found that people formed impressions of others based on their facial expressions in photographs. Whether the person in the photo was smiling determined if they viewed their personality as negative or positive. Their first impression from the photo even influenced how they felt about the person after meeting them face-to-face months after.

Everything from your posture to your furrowed brow is a form of communication. Stand upright, smile and if necessary, put on your Poker face.

20. Put away your phone

We've become so attached to our smartphones, tablets and wearable devices that it can be hard to disconnect. However, there are times when pulling out your phone is offensive.

Texting or surfing the Internet on your phone during a meeting is plain rude. Checking your Facebook feed or Twitter notifications in front of a customer reflects poorly on your company and will likely cause you to lose that customer and your job.

It's impossible to give someone your full attention when you are distracted by your phone, so put it away. Switch it to silent or turn it off completely.

21. Don't be a complainer

Nobody likes a Negative Nancy.

If you notice an issue that should be addressed, don't simply whine about it. (Of course, if it is an issue that violates workplace policies or moral conduct, you should report it to the appropriate person.) However, if it is anything else, think before you speak. Offer solutions and be careful how you broach the topic. Instead of expressing it as a weakness or a flaw, frame it as an opportunity to improve or an exciting new project.

The rules of business etiquette may change based on the location and culture. For example, how you start a meeting in the United States would differ from a Hispanic culture like Colombia. Diving right into business in the United States is not only normal but expected. If you do that in Colombia, it is viewed as rude and inconsiderate, which can negatively affect your business relationships. If your business is global or you travel internationally for work, research the business culture and etiquette. In some cases, people are understanding if you mess up because of a cultural or language barrier. However, showing that you are considerate of their traditions is appreciated.

You may not recognize it, but unspoken and implicit business etiquette exists in even the most laid-back company cultures. It can be difficult to figure them out at first, but following these universal rules can prevent you from making an embarrassing mistake.