I bring a few patches with nerd/chaos-related motifs, LEDs and other materials. You then sew them on and make them glow.
A little previous knowledge about embroidery is helpful, electronics previous knowledge is not necessary. If you want to embroider other things (jackets, bags, backpacks...), think about where the battery is not disturbing and protected, and bring it with you. If you have bigger plans, you can ofcourse take them home.
Children compatible (if there is some prior knowledge of embroidery (with the child or caregiver))