They are many kinds of challenges. In thirty days, you can read for twenty minutes in the morning; you can paint a  picture, finish the workout, or say hallo to everyone passes you. All of them are meaningful things if you have the strength to keep up, and after the thirty days, you might have already changed. For my own thirty days challenges, I decide to take five pictures each day with my camera. I want to take pictures of somewhere or someone appears beautiful to me, and record them a the symbol of a period of unforgettable time.