To begin, serge or zig zag around each edge of both pieces of your cut fabric. Place the piece with right sides facing each other. If you’d like to, pin the two pieces together.

Starting on what will be one of the sides, start a straight stitch seam about 2" below what will be the top edge of the bag. Stitch down the side to the bottom, pivot, sew across the bottom. Pivot, sew up the other side, ending 2" from the top.

Open your bag a little, to be able to flatten one of the side seams. Press open the seam near the top, using either your fingers or an iron. (I’m too lazy to bother with an iron!).

Starting at one top edge, stitch the flap of the seam down, ending just below where the original seam started.

Pivot, sewing a short seam across the bottom of this v shaped opening, and ending almost at the serged edge of the other side. Pivot, and sew the other side flap down, ending at the top edge.

Fold the top edge of the bag over 1", with the right side facing out. Press it down, again either with fingers or an iron. Repeat on the other side.

Sew a straight seam along the serged (formerly!) top edge of the bag, the whole way around. Stitch over the initial few stitches when you reach the starting point, then stitch back and forth a couple of times for extra security.

Turn bag right side out.

Run a cord through the top channel of the bag. Tie the two ends of cord together a couple times so that it forms a loop of the desired length. Trim very ends of cord, if necessary.