2 kinds of fabric, I used cotton as an outer fabric (thicker) and lining (thinner)
interfacing (I used middle-weight, woven, fusible interfacing )
1. Cut out one rectangle from the outer fabric (mine was 21 x 27 cm / 3 x 10.6 in). Cut out 2 rectangles from the lining fabric – first shorter by 1 cm / 0.4 in (lining), second shorter by 3 cm / 1.2 in (pockets). Fuse the interfacing on the lining piece.
2. First sew the pockets. Hem shorter edges of the rectangle – fold it twice, press it and then stitch.
3. Sew the pockets on the lining. Fold both pieces in half to mark the center. Pin the pieces together and make an “M” shaped stitch on the sides (see picture below). Perpendicular (to the side) lines are 3-5 cm / 1-2 in long (3rd photo). Then make 2 rows of stitching along the center line (1 cm from the center on both sides). These are finished pockets.
4. Sewing the zipper in. Place the zipper along the shorter edge of the rectangle cut out from the outer fabric (zipper’s front facing the right side of fabric). Place the lining on the top, and sew all the layers along the edge.
5. Repeat on the other side.
6. Unzip the zipper and sew the sides of the bag, leaving a small opening on one side. You can bend the zipper in half, but, personally, I always lay it flat – this makes it easier for the sewing machine to sew.
7. Now pin, sew and trim the corners. The side seam should be located in the center of the corner.