1 yard cotton or cotton blend fabric (this will make 6 coolers)
12" x 24" piece of 1/2" thick foam rubber
Directions
Cut fabric pieces 12-1/2" x 10". Cut foam rubber into 11-1/2" x 4" pieces. Cut a 3-1/2" piece of hook and loop tape.
Press one long edge of fabric under 1/2".
Wrap fabric around foam, overlapping folded edge over the raw edge of fabric in the center of the foam. Short ends of fabric should extend 1" beyond foam. Lengthen stitch to 8-10 stitches per inch. Top stitch next to fold. Stitch again 1/4" from fold.
With the seam side up, fold one end of fabric over 1/2". Cover with loop side of tape. Stitch tape in place. Stitch again to secure.
Turn wrap-around over. Fold end over 1/2". Cover with hook side of tape. (the hook tape and loop tape should be on opposite sides of the wrap-around.) Stitch tape in place. Stitch again to secure.
Supplies
Press 
With the seam side up, fold one end of fabric over 1/2". Cover with loop side of tape. Stitch tape in place. Stitch again to secure.