Back in January (2012) I've made a post on going repeatedly back to the same locations noting how much different they can look. It's really hard to make two visits the same. Different seasons, different times of day, different weather, changes simply as time goes by and things grow or get cut down, and more and more.
I really enjoy practicing that. It's kind of an extension of working the location. Even during a single visit, you can get closer, further, lower, higher, left, right, use wide angle, telephoto, vivid color, black and white. And coming back repeatedly just provides even more opportunity for variety.
The first image here, Submerged Rock, is fairly recent from spring 2012 taken at sunrise on a morning with a heavy coat of fog. Fog that removed color and simplified everything to just the basic elements.
The second photo, Lake Erie Sunset, is from the fall of 2011 taken at sunset on a cloudy, but otherwise clear evening. Definitely different. Which one is better is a rather subjective matter. Which one do you like more?
Revisit your locations and have fun!