People are often wrongly dressed for the interview. Usually they are overdressed, have on too much makeup and jewelry or impractical shoes.
When explaining decisions you have made, like why you are changing jobs, the interviewer is often interested in hearing about your motivations and attitude. Never complain about a former job or situation. Find a positive way to frame what you want to say.
Many people have negative speech habits, such as using hedges like just, actually, kinda and almost. Using them makes you seem less confident, less authoritative and therefore less employable. Don’t undermine your credibility.
At an interview talk only about the things that directly correlate with your ability to do the job: know your knowledge, skills and abilities. Talk about the job not your likes and dislikes.
Too many people walk into an interview with tons of extraneous items. Do not bring in your cell phone. Don’t bring in reading material. A water bottle may be acceptable but better off without a drink in hand. Companies hire people not just on a set of skills but take everything you do into account to determine if you fit in to their business.