Sticky backed plastic taped to the floor-sticky side up- lots of scrap paper- little tots will love sticking bits and bobs to the plastic and it is fairly mess free!! Once finished stick another sheet on top for stained glass effect!!
thread and scrap art! Lay "leavings" onto a piece of fabric, (thick enough but not to thick to sew over), place water-soluble fabric over top, and sew everywhere, wildly! Run water on disolvable fabric, let dry, then cut out shapes, and add hilighting stitching (leaf veins, outlines, etc.)