Here's a super-easy, super-quick project you could complete in an afternoon:
Plastic Bag Holder
Cotton fabric, pieced or solid, 20" x 25"
1/4" Elastic, cut to 10" and 6"
3/4" Ribbon, cut to 12"
As you can see, I took some scraps from a previous project and pieced them into a design I liked. I used a heavy cotton which kept the holder from looking lumpy once the bags were inside. You could design any pattern you like, and a solid piece of fabric would work just as well.
This holder is a bit over-sized because I had a large space on my wall I wanted to fill. You could easily change the height of the fabric to fit a smaller or larger space. Keep the 20" width, and adjust height however you like. No other measurements (for elastic or ribbon) need change.
Once you have your rectangle, lay it right side up and measure 2.5" down and 5" in from the left edge. Mark this point with chalk or disappearing fabric pen. Repeat with the right edge. You will sew the ribbon to these points later.
Next fold over the bottom edge of your rectangle 1/4" and press. Fold again 1/2" and press to make a casing for the elastic. Repeat with the top edge of your rectangle. Sew along the very outer edge of these folds.
Attache a safety pin to the end of your 6" elastic.
Insert the pin into the casing at the bottom of your fabric.
Thread the pin through the casing, taking care to stop just before the end of the elastic disappears.
Sew over this end a few times to secure the elastic. Keep threading the safety pin through the casing until you reach the other side, then sew over that end as well.
The bottom of your holder will now look like this. Repeat these steps with the 10" elastic and the top of your holder. (This elastic is longer to allow for stuffing lots of bags into a larger opening.)
Here's how the holder will look with the elastic in both ends.
Next, attach the ribbon to the points you previously marked. Fold the ribbon under and sew over a few times to secure.
Fold the bag in half length-wise with right sides together and sew ends with a 1/4" seam allowance.
Turn your bag out, and voilà!