Step 1: Select materials and preshrink
For the absobent panel, I repurposed tattered old cotton prefold diapers that had fulfilled their first duty as diapers for multiple babies and were approaching rag status. If you have no prefolds, or yours may either be re-used or sold, you might find ones in ragged condition you can get for nothing, or close to it. Otherwise, you can substitute anything you think will hold enough moisture, that your sewing machine can stitch through the layers of.
Step 2: Gather necessary tools and put in a new sharp needle
It's always a good idea to put in a new sharp needle with each project, but because this one may push the abilities of your machine to punch through so many layers at once, a brand new "quilting" needle is a good idea.
Step 3: Cut the middle panel out
Cut the smaller side panels from the prefold, leaving the thickest middle part. [Side panels can be used for another project, even cloth feminine products]
Step 4: Mark and trim
Cut the curved parts out.