And just when you thought you had all the details down, image consultants agree that nonverbal communication and business etiquette are just as important as appearance.

"You want to be very aware of your nonverbal communication, [including] your posture the position of your head, [and] what you do with your arms and hands," Thomas said.

A handshake contributes to an interviewer's judgment, so it should be strong and confident. To avoid clammy hands, Bowman recommends washing and drying your hands before the interview.

You should also sit up straight, Petersen says. A slight lean forward shows that you are listening.

"Both men and women should keep their feet on the floor...it's a more professional sitting posture," Thomas says. "When you cross your legs, you look a little more relaxed than perhaps you want to come across to your interviewer."

When you first walk into the room, you should wait for the interviewer to offer you a seat before you sit down. Don't touch anything on the interviewer's desk. Always address the interviewer with a title, either Mr. or Ms., unless you are invited to use his or her first name, Thomas says.

Of course, your nonverbal communication is not the only thing that matters. It is important to pay attention to the interviewer's behavior as well.

"If you're talking about something and they start to glance out the window or glance at their watch that's not a good sign," Thomas says. "You probably need to quickly regroup and decide what's not going well; perhaps you need to go off that topic."

And while the details of appearance and presentation may just seem like details, image consultants say that job applicants need a certain style before their substance can be judged.

If an inappropriate appearance or a late arrival distracts the interviewer, then your most important asset--your personality--cannot come through.

"These people that are interviewing you are going to assume that you have all the book knowledge," Bowman says. They're interviewing you...to see if you and your personality might fit into their firm."