The biggest criticism we hear from hiring managers is that applicants don't show enough enthusiasm for the position. Before each interview, research the company and gather as much information on whom you will be speaking with and what their role is. Listen to their questions and make your answers relevant and succinct. Being ill prepared and giving off the wrong verbal cues. Again, look your interviewer in the eye.
First impressions do make a difference in the hiring process.
In addition to being clean and neat, suitable attire is essential. For the most professional appearance, the best option for both men and women is always a suit. Men must wear a tie. Hair should be out of the face and conservatively styled, makeup light and professional, and no perfume or cologne. Do your market research.