Sew along the pinned edge. Stitch the other 2 pieces in the same way.
Place them as follows and stitch about 2 inches each end with a gap in the middle. This is for turning the bag through >
Then turn up the sides like you did for the outside of the bag and join the seams.
Do the same for the other 3 edges. You will now have this
Not much to do now. Position the handles on the right side of the bag at the tip of the pointy bits. Make sure the contrast fabric is facing the right way ( 2 right sides together ) I did this wrong on the first bag I made and had to undo it - aarrgh !
Place the bag inside the lining case making sure the handles are enclosed.
You can cut the small triangular bits of spare fabric off to make it easier when you stitch.
Pin around top edge matching seams and stitch.
Turn bag through gap in the lining. Get your edges nice and even and topstitch all around this edge. Slip stitch gap in lining fabric and thats it - you're done !!!
If anyone has a go at this I would love to see a photo. One of the nice things about this bag is that it is really easy to make it in different sizes. Just cut your squares bigger or smaller ! Hope this was clear enough !!