If this is not your problem, that you can skip this...
If so, here is a must read HOW TO: Tie a Tie. There are many ways to tie your tie, there are simple konts and fancy knots. Find one that you like and learn how to tie it. After you learn it practice, practice, practice, as people always said " Practice make perfect!"
Here is a great site that shows you how to tie your tie in a various amount of ways.
http://www.krawattenknoten.info/krawatten/Krawattenknoten/tieknot.html