PUL is pretty handy for this since it's slightly stretchy and soft, while still being water-resistant. Laminated cottons might work, but I think PUL is the best option. And, PUL is available at Joann's now! Other than a tiny piece of PUL (12"x 12" should be sufficient for most phones), a zipper at least 12" long is the only other needed software.
Okay, for sizing, phones vary considerably, and the idea is to have a pouch that just fits without excess bulk, so now we have to do some math:
- Length of the fabric = phone length + 1.5"
- Width of fabric = (phone width x 2) + 3" In other words, double the width of the phone and add 3" (NOTE: this will be longer than the length for the fabric, but it will be the short side of the pouch)
With the fabric cut, time to sew! With right sides together, line up and sew one side of the zipper along the short end of the fabric (which will be lengthwise when the pouch is finished). Position the zipper so the bulk of the extra length is on the end opposite the zipper pull. (This just makes the sewing down the road a little easier.)
Next, flip the zipper and fabric right-sides out and topstitch along the fabric edge. For this, I keep a firm hold of the PUL and keeping it taut as it moves through the machine so it doesn't shift or bunch up.
To lap the fabric over the zipper, the next step is to fold over 1" along the opposite side of the fabric.
And ready for it? IRON the crease. Yep, you can iron PUL if you're careful (and maybe have a window open :). Set your iron for a Poly setting and be extra, extra careful to not press directly on the laminated side.
This is what you should have now: zipper half attached and a folded edge.
Okay, we're going to stitch the other side of the zipper with the zipper open, so we first have to mark where the zipper should be pinned. With the zipper closed for the moment, line up the sides of the pouch and mark the edge of the zipper tape.
Open the zipper and align the non-teeth edge of the zipper along the "raw" side of the folded edge. of the fabric. The mark should be right on the edge of the fabric.
Being careful not to catch any other part of the pouch, sew along the zipper teeth to attach.
Turn the fabric right side out and zip it up to make sure it all works properly. :)
With the zipper still closed for the moment, turn wrong side out again.
On the "end" side of the zipper (opposite from the zipper pull while closed), cut off the excess zipper. Then, position the top zipper edge about 1/2" from the top side of the pouch. Peek inside to make sure the lap goes over the zipper from the top. Sew the seam of the side with the trimmed zipper.
Open the zipper first and then trim the ends of the zipper flush with the pouch sides. Clip (or pin) and sew along the side.
Turn the pouch right side out and you're done. Grab your phone, ID and cash (for a chocolate croissant, of course) and go out for a ride!