Also, dress presentably. This should be painfully obvious, but the amount of idiots go go into job interviews in their street clothes is staggering. Look like you give a shit and want to convey a professional image. Clean yourself up, put on a nicely ironed dress shirt and paints, a nice pair of shoes, and act like you have a lot to offer.

A big thing to keep in mind is you're trying to sell yourself, and they're trying to find someone who can be an asset to their company, not just filling a position because everyone needs a job and they're obligated. Learn what you can about where you're applying and what it does and offers, and thing of how you can relate your own skills into something that would be a transferable skill to the job you're applying for. Keep a good posture the whole time, keep enthusiastic and attentive, and basically make it seem like you want to be there. Also, turn your goddamn phone off. Mostly, if you get an interview, they're mainly looking at someone who is a good fit personality wise and to see if you match what you have on your resume and cover letter.