In previous jobs, and now in my role as a managing editor at CNBC, I've conducted dozens of job interviews.
I've seen the good, the bad and the ugly, and I'm consistently amazed at the very basic things that candidates screw up.
Here are the most common interview mistakes I see people make.
1. Arriving late
Since job candidates often have several interviews with different managers scheduled back to back, two things could happen when you show up late: Either your first interview is cut short, or you disrupt the schedules of several interviewers. Neither is good for you, since it either shortchanges your time with an interviewer or makes multiple people grumpy.
2. Arriving too early
On the flip side, arriving too early can also irritate a hiring manager, since it is equally disruptive to their schedule. It's important to arrive at least 10 minutes early to get through any security and check in with reception, but it's a mistake to arrive any earlier than 15 minutes before your scheduled interview time.
3. Appearing unpolished
Looking put together signals that you care about the interview and want to put your best foot forward. However, all too often people show up to interviews appearing rumpled, wrinkled, stained and wearing clothes that don't quite fit. It's not a fashion show, but it is important to carefully select your outfit, brush your hair and take a look in the mirror before you arrive.