The kindergarten students and I look at a bunch of prints by Henri Matisse (his shape ones) and describe what shapes and colors we see. First, the students quickly name the shapes that have names - square, rectangle, swirl - then they get into the organic shapes - bush, leaf, tree, octopus. We talk about how those shapes that look different to everyone are called organic shapes.
Next the students observe and report what they notice about the colors -- mostly solid, bright colors. Most of the time one student in class will observe how most of the organic shapes sit on top of geometric shapes.
After our discussion/exploration of Henri Matisse I demonstrate how to make geometric and organic shapes with my scissors out of scrap paper. I remind them how to use glue and turn them loose with their own papers.
This is a great lesson to work on using scissors while having everyone succeed in the learning target - a picture inspired by Henri Matisse.