I have cycled through a lot of kids in the last 8 or 9 years (?) I have taught co-op art. Some of my first students are long gone, so this year I am going to go back and use some favorite projects from the past, while still trying to develop a few new ones.
Quartered watercolor leaves are a favorite project I have done many times. It always gives nice results and is good practice for watercolor. You can NEVER get too much practice with watercolor! We folded our watercolor paper into fourths, then chose a color crayon and drew on the folds. Large leaves were positioned so that the leaf entered at least some of each square, then traced with crayon without too much tiny detail. Be sure the crayon lines are dark and thick. The crayon resists to help keep the watercolors from mixing. The student chooses two colors of watercolor and paints two backgrounds that are kitty corner from each other, then the opposite two leaf sections kitty corner from each other. With the second color they fill in the remaining backgrounds and leaf sections.
We work on keeping the watercolor transparent and using enough water to make it flow on the paper. One student took off and tried her own version with a butterfly and color crayons after her leaf project was done. This project can be used for different seasons (pumpkin? egg? ornament?) and works great for homemade cards.