3. Now lay the patterned fabric piece right side down on top of the zip and the plain cotton piece. Make sure the sides match up. Pin together these 3 pieces . You can feel the zip line through the fabric so you will be able to know where to pin. Sew.
4. When you pull the wrong side of the fabrics together, you will see that the zip is sandwiched between the materials and you can’t see the edge of the zip material.
Repeat steps 2 and 3 again for the other side.
You should then have it look like this, I call it a butterfly.
5. Now bring the right sides of the patterned fabric and the plain fabric together. Pin 1 cm from the edges. If you are including a wrist strap this is when you will sew it in. Also make sure the zipper pull is half way open so you can pull the pouch right side out at the end.
(For the wrist strap fold the strip of fabric you cut for it length ways, right sides together and press. Sew down the raw edge side, about 5mm from the edge. When you get to the end don’t cut your thread, instead pull the piece out until you have the same length of thread as the strap. Cut. Get a long needle and thread the cut end and use the long needle as a guide pull the thread through the tube you now have. Keep pulling the thread and then the tube will naturally turn itself the right way out.) Bring the two ends of the strap together and put the loop inside the bag between the right sides of the patterned fabric, the ends will poke out but lie in the path of the seam you are about to sew for the sides. Sew. Leave a 9cm gap at the bottom of the plain cotton end.
I then use pinking shears to tidy up the edges and get rid of excess, it also helps with the next.
6. Now squeeze one hand through that gap you left and get your fingers into the corners of the patterned fabric. You need to pinch together the two seams of the side and the bottom, from the outside you are looking to get a triangle shape. The seams at the bottom and the sides look like they’re making a T shape. Pin across 4cm from the point of the corner.
You need to do this for all the corners of the patterned fabric and the plain fabric. Sew.
7. I use pinking shears to cut off the excess. Now put your hand in the gap again, and pull the piece the right side out. Get your fingers poking into all the corners to make them all pointy. You will also need to sew up the gap by either slip stitching by hand or machine stitching the edges together. Push the lining back into the bag and again poke your fingers in the corners.
And there you have it. A flat bottom. As I said you can make varying sizes, just think about your scaling. Also the stiffer the fabric the more it will stand upright on its own as well.