
Tying the lace, accidentally unlacing them and tying them again is the routine for many a person so much so that it has become a routine is his life is not uncommon. Since, you don't actually pay attention to the knots you tie on the shoelaces.
The most common mistake a person does when he messes up tying the lace is the very first step. The key to a balanced and a tight knot is the first step. Always bring in the left lace over the right in the first step and then follow with a good loop.
Here is a link to learn the fastest shoe lace to save more precious seconds or embarrassing moments when you trip over your lace.
http://www.fieggen.com/shoelace/ianknot.htm
Want to know more about laces? Tying a proper shoelace isn't rocket science ;)
http://www.fieggen.com/shoelace/slipping.htm
(AW- Anil)