Gustav Klimt on of my absolute favorite artists but one I was absolutely fearful of attempting because so few of his work is kid friendly. My little my group of 7-12 year old girls studied the Tree of Life, The Kiss and some of his fully clothed portraits all the while looking for patterns.
To make our own Tree of Life they first used some shimmery fluid acrylic on the canvas to break up the whiteness. Once that dried we started from the base of the tree and worked our way up keeping in mind that a tree's branches are thinner as you go up.
For this, we used a combo of a few browns and matte fluid to make it easier to achieve the desired swirls.
Next we talked again about patterns or objects we'd seen: triangles, dots, birds, mushrooms, mushrooms with eyeballs, squares, blobs, flowers, a blanket, ect.
To spice things up you can have them work on each others for a minute to give some life to their neighbors painting and to gain inspiration for when they get back to their own.
If a kid got stuck, I had them flip their canvas to get a different perspective, this helped them focus areas that needed attention.
In the end some added caterpillars, bird houses, butterflies and even checkerboard games to theirs! Hey if Klimt can get away with the craziness on his tree then so can we!