So, full of ideas, I choose my fabrics from the stash for the Chinese takeout box purse.
The first step is to make sure they're well pressed. I'm also careful to lay them out right sides together - the pattern isn't perfectly symmetrical, so that's essential to making sure I'll have the right side of the fabric showing on both sides.
Cutting them out, I eyeball a seam allowance of about 3/8 inch and add it.
When I cut out the interfacing, though, I trim it to more or less the original pattern size. This reduces the bulk it will add to the seam allowance. Fuse the interfacing to one piece of your fabric. It should be a relatively heavy weight woven fusible interfacing.
Right sides together, stitch the two pieces together in an approximately 3/8" seam, catching in the edge of the interfacing and leaving as small an opening for turning as your patience will allow for.
Before you turn, trim the corners at an angle and clip to the internal points of the design. This will help make your corners more crisp and precise.
Turn the project right side out through the opening you left. A tailor's awl is helpful for making sure you're not missing any corners. Another useful trick? As a final step before pressing, insert your scissors, blades closed, and run the back of the closed blades firmly - but not too hard - along the entire perimeter of your seam. This will give you a more exact line and will coax out any stubborn bits that haven't properly turned.
Press thoroughly on both sides. Topstitch around the outer edge, catching in the opening you left to turn the work.
Now the challenge is to duplicate the folds of the box. I decide that as a baseline, I should topstitch an outline of the base through all the layers of fabric. To do that I need to transfer those four points to the fabric without the residue of the box coming in contact. So, I use my awl to poke a hole in each corner position on the original box, making sure the holes are larger in diameter than my pins. I layer the box, external side down, on top of the fabric, being careful to match them correctly (remember, it's not symmetrical), and pin through the hole into the fabric and the ironing board below.
This gives me my four points. Using a ruler and tailor's chalk - which I can brush away later - I connect the dots for topstitching.
With the topstitching done, I can begin to press in the fold lines, using the original box as a guide. I start with an up fold on each of the rectangular lines I just stitched, providing the basic outline of each box side. Then I press in the other direction the two "wing" sides that fold across and are attached to each other to hold the box in shape.
A quick pin test tells me this is working out.
Leaving the pins in place, I further establish the box sides by pressing from within the box on each side in turn.
A final bit of pressing creates guidelines for the top folds of the box. Voila! Looking pretty good!
At this point, if I wanted to have only one side ever be the "out" side, I could stitch the sides together - perhaps with a decorative button on either side - and add a handle and closure. But since I want this to be reversible, I have a few more steps coming up tomorrow.