Trace one of your CDs onto a piece of paper and cut out. You will use this as your template.
Sand the surface of each CD/DVD lightly, just enough to knock off any gloss coating.
Trace the template onto a piece of felt. Cut the circle out of the felt. Repeat this process for all of the colors that you will be using for your ladybugs.
Draw a curved line on your paper template for the ladybug's head (see photo). The shape will resemble a football. Cut it out and use it as a template to cut how ever many heads you need for your ladybugs using black felt.
Glue the colored felt circles to the CD/DVDs, then glue the black felt head pieces on top of the colored circles.
Use a round sponge applicator dipped in black paint to add spots to the colored felt on each ladybug.