To make a favorable first impression on a job interview, it takes good preparation. The better you prep yourself, the higher chance you'll have of being selected for the position over the other candidates applying for the job.
There are several things you can do ahead of time to prepare for your interview. Doing so will relieve stress and also give you more time to deal with anything unexpected that might happen on the day of your appointment.
Dress to Impress
How you look is likely going to majorly impact your interviewer's first impressions of you. Since the goal is to get hired for the job, you want the employer to sit up and take notice of you. If you dress to impress, this can go a long way in leaving that coveted positive first impression. Even if the dress code is casual, you want to err on the side of caution and dress it up for the first meeting.
When choosing your clothing, be sure to wear appropriate business attire and, if it has been a while since you've worn the outfit, be sure it doesn't look too outdated and that it still fits. If not, consider going out to buy a new outfit to wear to your job interview.
Before you leave the house, do a quick mental check of yourself. Did you remember to brush teeth, hair, and check to see your clothing is free of wrinkles? Take a quick peek in the mirror too. If you are doing a level of walking and planning to wear sneakers until you get there, be sure to remember to grab your dress shoes too.
Arrive on Time and Be Polite
In many societies, time equates to money, and being late for an appointment in these organizational cultures is typically frowned down upon. To avoid a potential late arrival, it is always a good idea to make a sincere effort to know where you have to go well ahead of the interview day. This is especially true if you aren't familiar with the area. If you are driving and are unsure of traffic patterns, whether or not traffic gets heavy at certain times or the day or how to get there, a good preparatory measure is to take a ride to the location well before the day of your interview. If possible, go at the time your interview is scheduled to take place so you get a good feel for the time needed to arrive to the interview on time. This way, you get a better feel for the flow of traffic during this time of day. Additionally, if you aren't driving, get familiarized with bus or train schedules and do your homework to make sure you catch the right time for public transportation.
Being punctual, if not early, will go a long way in making a stronger good impression. Also, when you get there, remember to make an extra effort to be nice to the person greeting you at the front desk. This person won't be interviewing you, but his or her impression of you might matter. According to The Muse, some companies ask their front desk people questions about interviewees. The article also recommends keeping your phone put away while you wait. 
Planning for your trip to the interview appointment ahead of time will not only make you more comfortable with the trip to the interview, but will significantly reduce stress on the day of the interview and ensure you get there on time.
Get a Solid Feel for the Organization
Potential employers love it when job applicants have taken the time to research the company or organization and are familiar with who they are and what they do. In fact, these days it’s pretty much expected candidates will have already researched the organization. It shows the interviewer an applicant is truly interested in getting hired for them and not applying for just any old job. Remember, the interviewer is also likely looking for someone who is a good match for the organization and, in most cases, this is not going to be hiring just anyone in order to have a body to fill a slot. The more you know about the organization, the better impression you'll leave.
Employers look to hire people who are willing to be knowledgeable because it helps them operate more efficiently when employees show interest in their jobs and the organization they work for; if you walk into the interview already having a good understanding of the business, you'll have a better chance of landing in the "potential hire" pile instead of getting immediately ruled out. Also, be sure to check out the organization's social media sites to see what they and others are talking about. This could prove valuable in having good questions to ask or just making conversation. It may even show you what topics you should probably avoid.
Practice, Review, Practice Some More
Equally important, brush up on your interview skills. You can't always predict what questions you'll be asked, but there are many you should expect. Know your own history and get your dates and facts in order, you don't want to display any inadvertent inconsistencies. Practice how to answer and what to say. Prepare for the unexpected questions so it doesn't throw you off-guard if it happens.
Additionally, prepare yourself not to start "rambling on" at any given point during the interview. If you tend to do this, you might want to practice ahead of time to create self-strategies to avoid doing it. Steve Fogarty, staffing partner at Waggener Edstrom, tells Monster.com this is one of the biggest mistakes he sees during interviews. He says people often get so caught up in what they want to say, they don't end up answering the question they were asked. Be concise. 
Also, you're sure to be asked at some point, "Do you have any questions for me (us)?" Have a few really good (not generic) questions prepared.
Be Sure Resume and References are in Order
Chances are you've already sent in your résumé, but that may have been to a human resources department, and the person interviewing you may or may not have your résumé readily accessible during the interview. It is a good idea to bring a few extra copies of it in case you need it or more than one person is present for the interview. Also bring along a few copies of a typed list of any references required or that the interviewer may ask you for. Be sure to have these documents organized in a professional folder or portfolio so they stay crinkle-free and are easily accessible in the event you are asked.
Early preparation for job interviews is a good way to relieve some of the stress that inevitably occurs with most job interviews. If you prepare early, you can then have clearer and stronger focus without getting distracted the day of the interview.