Many new hires are so anxious to make friends and a good impression that they often make mistakes that will leave them with neither. To ensure this isn’t you, check out the list below of 10 things you should be cautious of when you’re the new kid on the block:

1. Don’t tell your new manager how your old manager did things. Unless you were hired to be a change agent in your new position, your new company has little interest in how your old company handled things. Your new company has likely been successfully doing things the same way for a while, and there isn’t much that will scorch a manager’s ears like a new hire trying to change policies and procedures that have worked well.

Avoid saying things like, “That’s not how we used to do it at the Ajax Company.” It is almost certain that unless someone specifically asked how you did things at the Ajax Company, your new company doesn’t want to know. Use this phrase too often, and you could find yourself back on the street.

2. Don’t be too trusting of your new work mates. This doesn’t mean you should be a wallflower. It just means that you may want to remain somewhat guarded until you know for sure that the guy you think is just being nice isn’t looking for information to use against you or with which to embarrass you. Sounds creepy, but it does happen.

3. Don’t run to your manager about every little thing. New hires are expected to have questions concerning policies and procedures. Attempt to glean that information from those you are working with closely before disturbing your manager with petty questions that could make you appear to be either a brown noser or inept, either of which would be a bad thing.

4. Don’t be a “know-it-all.” Be willing to hear your new boss or co-workers out before jumping in with, “I know.” It may be that you do “know,” but you may learn something new by letting them complete their thought. Having a willingness to listen to instruction you may not think you need can be a great way to show a true desire to get along and be a team player.

5. Address those in authority properly. Just because your boss calls his boss by their first name doesn’t give you permission to do likewise. Asking permission to do so even when those at your level already do so is a sign of respect that will not be forgotten.

6. Keep your complaints to a minimum. You may end up with the worst schedule in your office or the desk chair with the loose wheel. Guess what? So did everyone else when they first started. Get over it. Do the best you can with the schedule and equipment you may have to work with. It’s not likely to go on forever and may teach you to have a little sympathy for the next new person.

7. Be who you want to be. The fun thing about starting a new job is that you get to reinvent yourself. Take advantage of your new surroundings by leaving the “old” you at your last job. This doesn’t mean you should pretend to be someone you’re not, just try improving upon who you already are—particularly if you didn’t like the person you were before.

8. Don’t take sides. Being new gives you the unique option to remain neutral in your new office. Take some time getting to know the dynamics of those you work with before engaging in situations you may not have enough information about yet. Coming down on the wrong side could mean a very brief career or an uncomfortably long one.

9. Keep time off to a minimum. If you had planned events prior to joining your new team, these should have been discussed and OK’ed before accepting your new role. Excessive tardiness and absenteeism looks particularly bad when you’re the new guy.

10. Identify and stay away from negative employees. Nothing shortens a career faster than feeding into the negative vibes coming from those who are unhappy in their position and use every opportunity to bring others down with them. These types really like to glom on to new employees, in particular, mostly because the rest of the staff won’t give them the time of day. Guard yourself from this soul-stealing monster at all costs, or suffer wallowing in the same stew.

Being new can be quite rewarding when you conscientiously avoid the little mistakes that can mean big trouble. So hold your head up, take a deep breath, and proceed with caution.