The alignment of the parts in the front and back of your car has a big part in wearing your tires evenly.
As shown in this picture, the camber and toe can wear your tires very quickly if out of alignment.
What can cause the Camber to be out?
Hitting a curb is the most common way. Large pot holes can also cause camber to move.
What can cause the Toe to be out of alignment?
This can also be caused by hitting large pot holes. Also when adjusting the lift of vehicles this can cause the toe to move.