Line is a good one to start with. The starkness of a Maine winter seems to favor this particular visual element. By processing the images in black and white, the simplicity of the composition is greatly enhanced.
These explorations are really a way to fine tune your perceptual skills. By focusing on only one element at a time, it allows your to push yourself to see the many ways it can be interpreted.
Line can occur in the space between two objects...in the negative space. Or it can be a dotted line when small objects, like fallen petals or stones, suggest a linear movement. Line is a fascinating element to explore...from the cracks in the sidewalk to the bare branches of a tree silhouetted against a grey winter sky. Look for lines in reflections as well as in objects...you will have no shortage of subject matter.
Why not chose one of the visual elements to explore over the next week? You can read about all the possibilities in this series I did awhile back.