• “All eyes are on you” during your first week of work, experts say.
  • In trying to impress your coworkers, there are miscues many new hires can make during the first few days.
  • Here are the mistakes to avoid during your first week of work.

First impressions matter — and at a new job, you want to be on your best behavior during the first week.

Job interviews can only tell both the employer and employee so much, but you won’t know how you truly fit in the company until after the first 90 days, Amanda Augustine, career expert at TopResume, tells Business Insider.

Augustine calls the first 90 days an “unofficial audition” for what your place will be at the company.

“You can interview someone until you’re blue in the face, but it’s not until you get past these first few number of weeks to know, ‘What really is this job like?'”

Like any audition, new hires need to put their best foot forward — and avoid making critical mistakes. Lynn Taylor, workplace expert and author of Tame Your Terrible Office Tyrant; How to Manage Childish Boss Behavior and Thrive in Your Job, says employees have a tendency to over-impress during the first week, which can lead to miscues: “You don’t have to become a superhero your first week, but on the other hand you do need to know all eyes are on you.”

Here are the biggest mistakes new hires make during their first week of work, according to Taylor and Augustine:

Don’t make any snap judgments in your first week, as it will take time to figure out your likes and dislikes at work.

Don't make any snap judgments in your first week, as it will take time to figure out your likes and dislikes at work.

As mentioned previously, Augustine says it takes 90 days to truly feel out your company. Your perceptions of who you like, the culture of the company, or the work itself are subject to change. “Judging this role by what’s going on by those first few weeks is really not helpful for anyone,” Augustine says. “It’s typically gonna change.”

She suggests asking questions to your coworkers and boss in the first week so you can get to know the culture, and will help you get into your groove at an organization sooner rather than later.

Don’t burn out quickly by staying too late and showing up too early.

Don't burn out quickly by staying too late and showing up too early.

When you first get hired, Taylor says there’s a tendency to still be in “sales mode,” where you want to continue to prove that you deserve your job. She says new hires fall into the trap of wanting to over impress their boss and coworkers, sometimes by coming in earlier than everyone else and leaving after everyone else is gone.

Taylor says working too long will burn you out quickly, and set a bad precedent for the future. For instance, if you start coming in later after showing up early for the first week, your coworkers will think you are slacking.

“You should demonstrate a strong work ethic within reasonable boundaries when you start your job,” she says.

Don’t be afraid of a fresh start.

Don't be afraid of a fresh start.

Augustine recalled helping someone who got hired out of college and were always treated as a kid, even years after being at the company. When the client moved to his new job, he decided to try to create a more adult persona and went by his full name instead of his nickname.

Many new hires can assume everyone at their new job has the same opinion their old coworkers had, Augustine says, but you have the power to forge a new path at a new company (if you start early enough).

Don’t eat lunch alone every day when you could be meeting new people.

Don't eat lunch alone every day when you could be meeting new people.

One of the biggest mistakes new hires make is eating lunch alone every day, Augustine says. After the first couple of days people may stop going out of their way to make you feel welcome, but it doesn’t mean you should stop taking the initiative to socialize with new coworkers.

While making new friends at work can be awkward, Augustine suggests asking what’s good in the area and if they want to join you out. “That’s a great way to informally get to know people in your department and get a better lay of the land,” she says. “You want a veteran rockstar on your side.”

While you want to be friendly, don’t bother your new coworkers.

While you want to be friendly, don't bother your new coworkers.

Scatter your introductions during the first week, Taylor says, and don’t just offer to do the same thing over and over; you want to personalize your introductions.

Avoid introducing yourself to your coworkers in the hallway or bathrooms, Taylor adds. Make sure they are available before you go up to them.

“You can stop by their cubicle and say hi, you can catch them in a break room,” Taylor says. “You have options.”

Don’t bring up personal details about your life right away.

Don't bring up personal details about your life right away.

“You don’t wanna be the person sharing every personal story,” Augustine warns. “They just met you.”

Augustine says this is especially important at happy hours or social events. She says it’s equally as important not to over indulge if there’s alcohol around; either keep it to a minimum or stick to soda.

Don’t stretch the dress code.

Don't stretch the dress code.

You don’t need to dress like you’re going to a job interview once you actually get hired, Augustine says. If employees typically dress in jeans and a T-shirt, going into work in a suit can signal you don’t mesh well with the company culture.

“You should be able to research the company culture,” Augustine says. “Dress for the job you want, but dress so you belong on the team.”

Don’t keep bringing up your old job.

Don't keep bringing up your old job.

“A trap that a lot of new hires fall into is they are always talking about their old company,” Augustine says.

If you were dating a new person and kept talking about your ex, don’t talk too much about what you used to have.

Don’t be afraid to showcase your ‘full skill set.’

Don't be afraid to showcase your 'full skill set.'

Often times in interviews, you can’t discuss every part of your résumé, Taylor says. During your first week, make sure your boss knows if you have skills outside of your primary role. That way, he can keep you in mind for projects down the road.

Originally Published on Business Insider.

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