Painting and sketching are the ways to express yourself. For some people it is their obsession, for others it is a way to relax their minds. While others consider it a way to make a connection with their inner-self. In any case sketching and painting are something intricate yet soothing and fascinating.
I believe that to display your art you do not have to be a great artist. You just have to draw you emotion and personality on paper.
My painting and sketching skills are poor to say the least, but I do enjoy woodworking to a reasonable level and find that it relaxes me. I think anything where you make something that can be considered beautiful can relax you, especially if it's very different to your day job.