plastic bag holder

Supply's needed...
8 strips of fabric measuring 20 x 3 1/2 inches (or more if  you want a longer bag holder)
2 pieces of narrow elastic (1/4 inch or smaller)  1 piece 11 inches long & 1 piece 6 1/2 inches
long.
1 piece of strapping, cording, or ribbon 14 inches long (used as hanger)
If desired, you can use one single piece of fabric 20x 25 inches
Thread
scissors/rotary cutter
sewing machine.

Lay out your strips in desired order, sew strips together along the 20 inch side.
Making sure to keep right sides together & using a 1/4 inch seam allowance.

When all strips are sewn together, press seams open.

Here all my strips are sewn together.

Next you will make a casing at each end for your elastic.
Note: (  I make sure to
make my casing along one of the 20 inch sides.)
Turn your edge over 1/2 inch and press.  Then turn another 1/2 inch
and press.

Next, sew as close to the edge of the fabric as possible without sewing off the edge.
Repeat this on the opposite end for your second casing.

Now you will attach your hanger.   Pin your strapping (or whatever you are
using for your hanger) just below the seam for your casing.  Lining  up each side
so that your hanger is centered.

Now you are ready to insert your elastic into each casing.
Begin by attaching a safety pin to each end of your elastic, this way
if you accidentally let go of the elastic you can retrieve it from inside
the casing.

Insert one of the safety pins into your casing and thread your elastic
through  by pushing and pulling it through the casing.
Repeat for the other end.
Make sure to use the 11 inch piece of elastic for the top of your
bag holder, and the 6 1/2 inch piece for the bottom.

Elastic at the top of bag holder
Note: leave the safety pins attached to the elastic until you have
sewn the side seams.

Elastic at the bottom of bag holder.

Line up side edges, being careful of the safety pins, and making sure
to back stitch at the beginning and end, sew side seams.

Turn your bag holder inside out. 
Next stuff all those plastic bags inside your new bag holder!