The first impression of yours that crosses the mind of an interviewer is the last impression they'll have about you. This means you need to know what to do in your job interview. The interview can be frightening at times for many people but don't worry we got you covered. The interview for any job ranging from technical ones to applying for a school teacher. A smart person knows to prepare himself well before going for the interview. If you have a stunning impression of your personality on the interviewer, you got hired. But if you fail to influence the views of the interviewer, you'll lose the job immediately. It's best to research a bit and see what you need to know beforehand.
Know the job requirements: 

If you're going to apply for a job vacancy, it's a must to know the requirements well. This will give you a sense of confidence that you're competent for the job. If you're not eligible for the job and you apply for it, you're going to be embarrassed later. Make sure you're qualified enough exhibiting all the skills, knowledge and qualities they expect. 
Dress well for the interview:
Best to decide this one before going for the interview. You should wear something that gives a sense of professionalism. Your suit should be cleaned, pressed and have a good fitting according to your body. Get a nice tie according to your suit, shine your shoes nicely to give a good impression to the interviewers. Make sure to have a neat beard along with a nice haircut. Use perfume as well to seem to smell good to the others.  
Be punctual: 

Being punctual never goes out of fashion. Prepare all your essentials early in the morning to avoid any complication. Being late at first will affect your anxiety level which will ultimately result in making you more nervous than ever. Being late on your job interview will give an impression of irresponsibility to the interviewers. This can extremely affect your job hunt. 
Be positive and enthusiastic: 

Having a positive and enthusiastic approach to your life can get you amazing results. For such an attitude, have enough sleep before the interview so that you don't look exhausted. Have some exercise in the morning to be active throughout the day. Eat a decent breakfast to start your day and smile more to have an optimistic mindset. 
Be confident and honest: 

Confidence is the key to success. Look confident by making sure you're the best possible candidate for the job. Being honest will do wonders for you. Don't be blunt but honest. Answer all the questions in the best possible manner by being honest about your qualifications and experience for the job. Lying can land you in hot waters because companies make a background check on every candidate.  
Practice before the interview: 

Doing a bit of practice before the interview can make you more confident as you've already practiced your way through the interview. Ask a friend to ask you questions you think would be asked. Practice being polite to everyone, to shake hands, to make eye contact, to sit properly on the chair and to be attentive during the interview. Practicing all the etiquette will infuse your personality with the best possible version of yourself.  
Prepare your questions: 

After the interview is done, you'll most probably be asked if you have any questions. This is an important part that you need to cover before the interview. Make a list of a few questions you're going to ask the interviewers. Memorize those questions and ask them in the end. This will give the notion that you're well prepared for the interview.  
Leave with a charismatic impression: 

After you're done with the interview following all the guidelines we've mentioned before. You're now going to leave a charismatic impression behind by greeting them farewell and thanking them for the interview as well as their time. 
Here we've mentioned the few best practices that you could adopt before appearing in a job interview. Follow these and you'll succeed in securing the job. Best of luck!