"Keeping people waiting can be construed as inconsiderate, rude, or arrogant," Randall says.
Being negative all the time
Repeatedly responding to suggestions with a pessimistic or contrary attitude can be construed as being uncooperative, Randall says. Phrases like "That won't work," "That sounds too hard," or, "I wouldn't know how to start," should be avoided.
Similarly, complaining too much puts you in a bad light.
"While there may be times when everyone feels the desire to complain about the boss, a coworker, or a task, voicing it will only make you look unprofessional," Randall says. "It's even worse if you complain every day, all day, from the moment you walk into work. Before long, people will go out of their way to avoid you."
"There's nothing as energy-draining as having to deal with a pessimistic coworker," Rosemary Haefner, chief human-resources officer for CareerBuilder, tells Business Insider. "Things do go wrong, but even when they do, focus your energy towards what you've learned from a bad situation."
She points to a recent CareerBuilder survey, which shows that a majority of employers — 62% — say they are less likely to promote employees who have a negative or pessimistic attitude.
Talking about polarizing issues unrelated to work
"Before you pull up your soapbox, you should be aware that in most cases, free speech in the workplace is limited or non-existent when it comes to controversial movements or topics," Randall says.
As an employee expressing yourself at work, it turns out you have fewer protections than you'd think — and if your boss doesn't like what they hear, you could get fired for it.
Unless you signed some sort of contract that says otherwise, it's likely you're an at-will employee. This means that your job can be terminated without having to establish just cause.
There are labor laws that exist in the US to protect people against adverse employment actions due to discrimination. So if your boss fires you, for example, simply because you're a woman, that's wrongful termination, and you could sue them for that.
But very few laws exist that truly protect private sector employees against getting fired for expressing their political affiliation. There are a handful of states like New York and California with laws offering protections for political affiliation, but even those are fairly limited.
"Before you go cubicle to cubicle enlightening your coworkers about your cause, read the company policies and procedures manual. Most companies discourage or forbid promoting personal causes, especially on company time because it's deemed disruptive," Randall says.
Spouting off on social media
Your company may have specific policy outlining how you may use social media, so it's always a good idea to get acquainted with your employee handbook.
But generally, many employers take a negative view when you use social media to complain about your boss, coworkers, or clients, share company secrets, represent the company in a negative way, or make offensive comments.
Being on Facebook all the time
Even if you're not writing anything offensive, being on Facebook every time your boss walks by looks really bad, Oliver says. Unless it's work-related, many companies frown on using social media during work time, and especially using work equipment.
Playing '20 Questions' on every new assignment
There may be no stupid questions, Oliver says, but there are certainly annoying questions. These are the kinds of questions that prove you really don't want to do the assignment or illustrate you only want to hear yourself talk.
"When you receive a new assignment, gather your questions, and pose them in an organized way," Oliver suggests. "Never just spout out question after question off the cuff."
Practicing poor hygiene and grooming
You want to look like you take your job seriously when you walk into work, and your hygiene and appearance play a role in that.
"Poor hygiene and sloppy clothes scream, 'I don't care!' and are a surefire way to put off those around you," Randall says.
Your boss may wonder whether your attitude about how you present yourself extends to your work, she explains, and you may be passed over for a promotion, overlooked when it's time to meet with a client or represent the company at a conference, and not invited to social gatherings.
"Whether you're at your desk or in the break room, being known as the office slob is never a compliment," says Randall.
When you clog the office kitchen sink and leave your garbage around, who exactly are you expecting to clean up after you?
"Leaving your mess behind shows lack of responsibility or consideration, arrogance, and immaturity," Randall says.
Similarly, your workspace can be a reflection of you, she says.
"If you're like me, who works well in a semi-messy environment, it can be inhibiting to be clutter-free. But with open cubicles or workspaces, the professional thing to do is to make some compromises," Randall says. "It would be disrespectful and inconsiderate to expect your coworkers to deal with your mess."
According to Haefner, employees who don't clean up after themselves can hurt their chances for a promotion in the eyes of 36% of employers.
Calling in sick when you aren't
"Remember the adage that half of life is showing up," Oliver says.
You won't prove you deserve the promotion if you call in sick every few weeks.
It seems like almost every office has one or two people who sell cookies for their kids. But Randall says that some companies prohibit soliciting at work because it takes up work time and places people in an awkward position. Breaking the rules could be grounds for firing.
Being distracted during meetings
"There is a reason why texting is illegal while driving: It's impossible to concentrate fully on two things simultaneously," Oliver says.
Texting, surfing the web on your laptop, instant messaging, emailing — doing any of these things during a meeting shows everyone else in the meeting, especially your boss, that you're not paying attention.
"They know that while your butt may be planted in the chair, your mind is roaming," Oliver says.
Making personal calls all day long
Talking or texting with friends or family on company time is unprofessional and could be against company policy, Randall says. What's more, doing it during a break is fine, but these correspondences should be kept out of the workplace, even the lunch room.
"You never know when your boss may walk by for an impromptu chat," she says. "What will they see or hear?"
"If the topic of conversation is of a delicate nature, be sure to keep it private. One overheard juicy tidbit can spread like wildfire," Randall says.
"Maybe the new guy who smells like French Onion Soup is not your favorite person on staff," Oliver says. "That's no reason to flee him every time he asks you for help on an assignment." Nor should you be spreading gossip about him, Haefner says.
It's best to act friendly toward everyone, Oliver explains: "You will come across as more of a team player and show you have management aptitude."
"Take care that any criticism you make about someone's performance is deemed to be constructive, measured, and deserved," Oliver suggests. Not keeping the discourse civil could cost you your job.
"There is a line between curiosity and nosiness, which you don't want to cross," Oliver says. Curiosity, she explains, is when you ask who the new hire is. Nosiness, on the other hand, is when you rifle through your boss's files to see how much the woman three cubicles down earns.
Raiding the supply closet
Taking home a yellow pad of paper and a few pens if you're going to be working from home all weekend is acceptable behavior. But when you raid the supply closet and stash pads of paper, flash drives, notebooks, and folders, you're essentially stealing money from the company, Oliver says.
"Ask yourself if you are really using it for work. If not, leave it be," she says.
The same rule applies for using the phones to make long distance personal calls and using the Xerox machine to make copies of your great American novel.
Drinking on the job
Some employers stock beer in the fridge and host weekly happy hours. Others do not. If you work for the latter kind of company, drinking on the job is an easy way to get yourself fired. In fact, a survey by The Ladders of managers who have terminated employees for office etiquette offenses found that 35% of bosses surveyed have fired people for boozing at work.
Even if social drinking is part of a company's work culture, it's still not a good idea to drink at work so frequently that you become labeled the office drunk. This rule of thumb also extends outside the office at company gatherings and happy hours.
Looking for another job while you're at work
Just like being on Facebook or making personal phone calls all day are inadvisable, it's especially poor form to spend company time on your job hunt. You might as well ask your boss to fire you now.
Even mentioning your job search to coworkers could pose a serious problem. They may share, intentionally or not, that you're looking for another job, "which could explain your lack of productivity and absences, resulting in a poor reference or an invitation to pick up your paycheck earlier than you expected," Randall says.