A weak handshake may indicate passivity and you will have to work even harder during the interview to change the employer's opinion. Professional dress is expected for the interview. If you have tattoos, long hair, etc., you must consider the environment where you will be working. If hired, you are a projection of the company's desired image. Smile and show enthusiasm and interest in the company and the job for which you are interviewing.
Body language is important.
Unwillingness to relocate is a negative for employers, as is using an interview simply for practice. It is acceptable to ask if you may take notes during the interview. Always bring written questions to ask the recruiter. Many employers stated that they appreciate receiving thank-you letters, not cards, from the students after the interview. They use thank-you letters as another source for a writing sample.