Unfocus your eyes and see what textures jump out at you. Try texture rubbings so children can touch a variety of patterns, and let children label the rubbings in their own ways. Encourage them to compare and describe their work. Others are slow, subtle, or delicate, such as the changing color of the goldfinch's wings from brown to bright yellow as spring arrives. The texture of the ground changes from smooth to crunchy, mushy to hard.
Water changes from liquid to ice, and back.
Colors change, rhythms change, and sounds change. Obviously, it is easier for children to observe and record changes that are immediate, but long-term change can be even more satisfying as children hone their observation skills. Try observing the natural world from a fresh perspective. Look at something upside down, climb above and look down, get nose to nose, check out the underside of a common object. Each view can add new insights, raise questions, and open more thoughts.