For your situation: I always recommend sending a thank-you note (handwritten) within a couple days of the interview. Keep it short and sweet, its a good way to show that you appreciated being considered for the interview and makes them think of you. (always a plus.)
Other tips for interviewing really depend on the type of job. My advice pertains to a professional interview, and keep in mind that I work in DC and we are generally more a conservative than other places.
Appearance: First and foremost, appearance really matters. If you won’t take the time and energy to present yourself well when trying to find a job chances are you won’t put the effort in to the actual job. Ideally shave your face completely, at the very least trim your facial hair so it is clean and looks good. Get a hair cut a couple of days before the interview, and brush it/style it so it looks nice for the interview. Cut your nails, brush your teeth. Wear a basic blue/gray suit and tie with a white or blue shirt, have a tie that complements the colors of your suit and shirt. Socks match the pants, and I recommend black shoes and belt. You appearance is not where you want to stand out. I have never heard of anyone offering a job because of how someone dressed, but I have certainly heard of people losing the job because of it.
Interview Prep: Do your research on the company you are interviewing for, and if possible find out as much as you can about the interviewer. If you have something in common with them (same schools, fraternities, sports, favorite teams, hobbies, whatever), you can use that during the interview to your advantage. As for the research on the company, you always want to make sure you have something to say when they ask if you have any other questions. I interviewed for a job which I was offered at a ‘small’ business (couple hundred employees) that was in the process of being acquired by a large international corporation. After we went through the standard questions we talked about that process for about fifteen minutes, which I think played a big role in the job offer.
Day of the interview: Eat a good meal, if you are a coffee drinker make sure to have your coffee. Drink a bunch of water, when you are nervous you will get dry mouth. I highly recommend doing a light workout in the morning also (I recommend working out EVERY morning, but thats a different story), it WILL help out your mood. Leave with enough time that you will arrive AT LEAST ten minutes beforehand. Bring a couple of copies of your resume, a notepad, pen, and list of notes about the company/interviewer and questions to ask.
The actual interview: I recommend showing up between five and ten minutes before the interview is scheduled. You want to be early but being too early can be an inconvenience. If you are offered a bottle of water, always accept.1 If you are waiting with the receptionist for any amount of time, try striking up a conversation with them. They will likely be asked their opinion of you and I assure you it matters. When the interviewer shows up, give them a firm handshake and make eye contact when you greet them. Offer them a copy of your resume, and have one out in front of you. Some people will disagree with this, but I always suggest asking if you can take notes and then actually taking the occasional note. You have questions prepared and will want to write down the answers. Make sure that if you do take notes to not have it become a distraction or a way to avoid eye contact. Give lengthy answers to any of their questions, try to avoid cliches or one word answers. If at any time you notice an awkward silence forming it is because they want you to expand on your answer, this is a trick taught to interviewers.
The most important thing to remember in an interview is that you are competing with other applicants and want to set yourself apart from them. Everyone is qualified for the position, the entire point of the interview is to find out if you can present yourself in real life as well as you do on paper. (And to see if your personality is a good fit for the office.) Your entire job is making them remember you. I’m not suggesting taking a shit on the interviewer’s desk, but you do want to stand out. The more time you spend talking about things OTHER than what is on your resume or cover letter, the better off you will be. Making a real personal connection with the interviewer will help you so much. I interviewed someone who had just come back from a post-college ‘pilgrimage’ to Germany (they were like 50% german and I’m like 75%). I had taken a trip to Germany before, and we spent a long time talking about his trip, where he stayed, everything. Its why I chose him over someone else, because I knew he was an easy guy to talk to and frankly made me remember him when it came time to decide who to cut.
Thats all I have for now, if I think of more I’ll add it. This is all pretty basic, and directed toward fairly entry-level jobs. Those are the jobs I interviewed for the most and have started interviewing others for.
1 In one of my first interviews, I was offered a cup of coffee because the person interviewing me was grabbing one. I thought I would be polite and decline, and he chastised me for it immediately. Not in an offensive way, he was just the “no-bullshit” former military type of guy. He told me that people want to be helpful and that rejecting their graciousness can be pretty insulting. If offered, accept.
TL;DR: Look nice, be prepared, don’t trip.
Edit: Couple other things I wanted to add.
Hard questions you should be prepared to answer:
- What are your biggest weaknesses?
- Why should I hire you?
- Tell me about yourself (expect a long silence after this one.)
- Why do you want to work for us?
- Why are you leaving your (last/present) job?
- What are you long-term goals?
Good questions to ask:
- As stated above, ask a question demonstrating you’ve researched the job or position.
- My favorite: What are the opportunities for advancement at (organization/position.)
- Above question could also be worded like: What is the typical career path for people in this position?
- Do you have any concerns about my qualifications for this position? (Careful with this one!)
- Never ask a question that a google search or research on website can answer.
Last thing for now – When you first enter the office of the interviewer, look around at what they have that you can talk about. What books are in their bookcase? Pictures of family traveling, pets, etc. Again, your biggest concerns are not shooting yourself in the foot and making them remember you.