( this is only a sample, we would like them in different fabrics for each, check out Jan-Maree's blog and you can see all the wonderful different bags )
2 pieces of fabric, one is for lining and one for outer Laundry bag about 42/44 inches x about 30 to 32 inches ( I made this one just using a sheet to show you, would make the outer different, maybe even a heavier fabric)
one 4 inch strip x 42 inches ( casing for the cording )
Cording about 50 inches
cut selvage off, fold width in half and stitch the the two seams, down one long side and the bottom, repeat for lining but leave a gap ( see second picture ) in the bottom for turning inside out later.
Outer Bag and Lining will measure about 21 inches by 30 inches ( not that important as long as the two measure the same)
Fold the two ends of 4 inch strip twice ( about 1/2 inch each time) and do a triple row of stitching just to make it a little stronger.
Fold in half length wise with right side out. You can see in the picture below that the strip will be shorter than the with of the bag.
Pin to the right side of the outer Laundry bag with the raw edges matching and stitch, turn the outer Laundry bag right side out, see picture below
Now tuck in the outer Laundry bag inside the lining bag and match the seam and stitch around the whole bag, you can now pull the outer bag through the gap in the bottom of the lining. Stitch the gap and push the lining inside the Laundry bag.
Topstitch around the bag just as picture and feed in a cord.
Hope this makes sense, please email if you have any questions.