Wikipedia defines gratitude as “a feeling, emotion, or attitude in acknowledgment of a benefit that one has received or will receive.”
If we are able to live a life with gratitude it means we will live a life with less depression, better relationships, and increased overall happiness.
[1]  The law of attraction says that you attract into your life what you are thinking about.  While this may not always be true it does seem that if we think about things with a positive framework it contributes to our well being.  We have all met people that speak of everything negatively and usually they are really unhappy people.  People that are able to be thankful for what they have are more able to deal with negative experiences as an exception, rather than the rule.  Bad things happen to all of us but if we look at these things as obstacles rather than a personal attack we will move through the negative experience faster. 
How can we practice gratitude?  I suggest saying thank you as a first step.  Say thank you whenever anyone does anything nice for you.  You will be surprised how often you are saying it.  Another thing to try is spending some time each day thinking about gratitude whether you write in a journal or just spend a few minutes at the beginning or end of the day focusing on what you are thankful for. 
Often we become complacent and don’t pay attention to the things that are important to us until we risk losing them.  It is important that we not take our relationships for granted. 
Another way to express gratitude is to do something nice for someone.  Pay the toll for the person behind you in traffic, take the time to listen to someone who doesn’t normally get listened to, and/or donate your time or money to a worthy cause.  These things both make us feel better and make others feel good too. 
“Feeling gratitude and not expressing it is like wrapping a present and not giving it.” –William Arthur Ward
Why not make an effort through the next week to express more gratitude and see whether or not you feel differently.  
I’d love to hear your comments on this. 

[1] · Wood, A. M., Joseph, S., & Maltby, J. (2008)., Gratitude uniquely predicts satisfaction with life: Incremental validity above the domains and facets of the Five Factor Model. Personality and Individual Differences, 45, 49-54.