I am no Emily Post, but as a person who dedicates herself to helping people get noticed, valued, promoted and hired in their high-level careers, I think this list is important to publish.

In order to make the list, the offending habit had to meet all three of the following criteria:

1. The habit is often subconscious to the doer.
2. The habit is highly offensive to the observer.
3. The habit might be acceptable to your loved ones and intimate peeps, but risks impacting your professional reputation at work.

1. Chomping, slurping, smacking, sucking, and other gross things with your food. Once your food (or gum) makes contact with your mouth it should never be audible or visible to your meal mates. Ever. Not even if it’s finger-licking good.
2. Passing gas and belching. This habit made the list not because of the occasional slip which is part of being human—it made the list because some people do this at work or on public transport and think it is perfectly “natural” or funny. It is neither.
3. Excessive throat clearing. Hey, we all clear our throats occasionally, but if you can clear a room when you clear your throat, you might want to pay attention and try to determine if it is an unnecessary habit.   
4. Loud and honking nose blowing. If you always have a runny nose or are at the tail end of a cold, you may wipe your nose discreetly during a discussion or meeting. But if you have to blow big, excuse yourself and do so privately or at least outside of the room. If you have to do it repeatedly, go home sick or get your sinuses checked.
5. Audible phlegm ingestion. It took me a long time to figure out how to say this. This is the habit of ingesting or recycling internal contents that should be discarded into a tissue. It comes with a real “show-stopper” of a sound that many people are completely unaware they are doing.
6. A cloud of cologne or perfume. No one should spray perfume directly onto the skin or clothes. Instead, spray the air and walk through it. Also, be aware of how strong your body and hair products can be—especially when combined.
7. Picking your nose, teeth or skin. Use a tissue or toothpick if you must, but do these things in private or discreetly.
8. Body odor or bad breath. So many things impact body odors and sometimes finding the offending cause is confounding—but the bottom line is that it is everyone’s personal responsibility to look after this aspect of sharing airspace with other humans.
9. Sneezing or coughing without covering your mouth/nose. Turn your head, use a napkin or your arm—literally anything is better than nothing. A sneeze can travel upwards of 20 feet and a cough can travel 6 feet.