Whether you are going to an informal or formal business interview, make sure to wear a tie. Wearing a tie will make you look more sophisticated and professional. Ties come in a variety of colors and designs, but this does not mean you should wear colorful ties or ties with pictures on them. Avoid wearing those kinds of ties if you want to show that you are serious about the job and want to leave a good first impression. Choosing solid colors like navy or black would be a good idea for an interview.
Wow, I did not realize there are 85 ways to tie a tie! Well here is a website with lots of information about ties and step by step instructions on how to tie a tie. http://www.totieatie.com/
Which one would you wear?
Also, take a look at some of these helpful videos.
How to Tie a Tie in 3 Different Ways
Four In Hand, Nicky Knot, Full Windsor Knot Plus Dimple Tutorial