We determined a good size for now is 26" x 16" with rounded corners. I used cotton quilting fabric, and backed it with Sew Comfy (JoAnn's), and added a layer of PUL inside to make them waterproof. That way, I could have a pretty fabric on one side and a soft fabric on the other side, and still have them baby-poop/pee-proof :-)
I used some strips of exam room paper (gift-wrap tissue would work too) against the PUL when I sewed the layers together to keep the PUL from sticking to the sewing machine plate. Then turned the sandwich out through a 3" opening, and topstitched the finished pad.
I love the "Just Stay Little" saying on this fabric...oh, if they could just stay little a little longer :-)
Miss Piggy photo-bombed my pic!