I always check the remnant bin at JoAnn's Fabrics and other fabric stores. They always seem to have small yardage marked down to half price. 1/2 to 1 yard pieces that will make several pouches for your gliders and plenty of 3-4 inch square pieces for your gliders to snuggle with.
I order mine online from Joann Fabrics- you can even go into the store. Make sure you get anti-pill fleece. They sell tons of scrap pieces for cheaper as well.. & if you check online first you can always get a coupon!
Depending on where you purchase your fleece, Polar fleece or Blizzard Fleece is good fleece as well, I prefer them over anti-pill. Also, I have used the fleece throws, make sure you remove the stitching around the edges.