A weak handshake. Poor eye contact. Slouching in the chair. Lack of enthusiasm. Sloppy grooming. Smoking. Hostility. Boastfulness. Condescension to the secretary or receptionist.
out of 100 bothers to research a company before a job interview. One out of 25 has prepared questions about the job or company. One out of 10 works at selling himself or herself. One out of 3 walks in without a resume. And only one out of 50 follow up the interview with a note to the recruiter.