I decided to stitch a prototype first before sewing the box I intend to give as my gift and I am so pleased that I did. It isn't quite finished as yet but I think I have worked out everything that can go wrong. At least I hope so.
Firstly, the interfacing that is recommended is very stiff and bulky, which is great to support the shape, but horrible for seams and hems. So I turned a hem at the top first so that the interfacing sits in the fold.
I followed the instructions and cut out the fabric and interfacing , sewing the two together around the edge and then quilted them. It worked but I think I will quilt first and then cut out the shape . Another problem was of my own making. I thought I would use a gold metallic thread for the quilting. Big mistake. The thread just broke, so I switched to a rayon thread and got a better result.
And those clips around the edge. I couldn't find my quilting ones so used some clear pegs from Ikea. They do a terrific job at a fraction of the cost. Now to finish the real thing. I have to have it done by 3:30pm so I can catch the 4pm ferry.