This easy bag has a self-closure and incorporates 3 cool tricks, 2 of which I figured out from studying bags I liked, and one which I made up myself. All 3 tricks save time and materials, without compromising the bag's quality. This is a great bag for carrying shoes, your lunch, or other small items. You can make up a smaller version out of a stiff fabric (e.g. leftover upholstery material) as I did with the yellow and red bag to use as an evening bag or wristlet. These easy bags are so quick to make, you can create one to go with every outfit! They also make great gifts.

Step 1: Select 2 Coordinating Fabrics

You will need 2 coordinating fabrics.

For main bag fabric, cut piece 11" wide X 30" long.
From accent fabric, cut trim piece 11" X 3", and handle/strap piece 14" X 3 1/2".

The bag size can be easily varied - these measurements are designed for a woman's shoe bag.

For the smaller evening bag, I cut 2 pieces of the main bag fabric 7" X 6" and 7" X 5" and inserted a 7" X 4" piece of red accent fabric in between these two pieces, as I wanted to highlight the boxed bottom, which didn't show up very well in the blue cotton fabric. The red trim piece at the top, which is sewn to the shorter piece, was 7" X 3". The wristlet red strap piece is the same size as for the larger bag, 14" X 3 1/2"

Step 2: Add Trim Piece and Make the Fake Bound Buttonhole (1st Trick)

Sew trim piece to main bag piece with a 1" seam, leaving a 2" opening in the middle (you will sew 4 1/2" on either side of the buttonhole). (Use 1/4" or 1/2" seam allowances on all other seams - this is the only seam that needs a wide seam allowance)
Iron seam flat.
Topstitch close to the edge all around the 2" opening, making sure the seam is flat.

You now have a neatly finished, "bound" buttonhole - in less than 1/10 the time it would take to make a true bound buttonhole! This is a very secure and neatly finished opening, which I like better than using a machine zigzag or buttonhole stitch.

Step 3: Give Your Bag Shape by Creating a Boxed Bottom (2nd Trick)

Iron your bag, wrong sides together, lining up top edges,and ironing the bottom fold.
Now take a ruler and measure 1 1/2" up from the bottom and fold top layer of fabric over this (see photo).
Iron this fold so the crease is clear.
Turn bag over, and do the same thing on the other side. The bag now has right sides facing together, and an inverted pleat in the bottom, which I am trying to show in the 3rd photo.
Pin, especially at the bottom to ensure pleat is neatly enclosed, and sew or serge the 2 side seams. Turn bag right side out.

There is a good video showing how to create this boxed bottom - it is the 3rd of 3 methods shown at https://www.youtube.com/watch?v=1e1l_FMnp9I

The last photo shows the boxed bottom, in a stiff upholstery material. For this small purse, I made the "box" or base of the bag quite wide - the red fabric insert was 4" wide and finishes as a 3 1/2" base for the bag. The pleat formed in steps 2, 3 and 4 above was 1 3/4". You can vary the size of the pleat, and therefore the box, depending on the shape and look you want.

NOTE: This entire step is optional. You could leave your bag flat and omit the boxed bottom, and just sew the side seams. This makes sense for a bag from soft fabric, like a cotton shoe bag, where the boxing doesn't really show up. For a purse from a stiffer fabric, a boxed bottom is very nice and enables the purse to stand up on its own.

Step 4: Finish Top Edge of Bag

Fold down 1/4" of top edge of bag to wrong side, and iron. Fold again so there is no exposed raw edge, and iron.
Sew folded edge down close to edge. Your stitching should cover the raw edge of the accent fabric seam allowance on the front side of bag, as in the 3rd photo above.

Step 5: Sew Strap and Attach to Bag

Fold the 14" X 3 1/2" piece of fabric in half lengthwise and sew, right sides together.
Turn this tube right side out and iron flat. For an easy way to turn the tube inside out, see this instructable. Fold raw edges (about 1/2") at the ends of the tube to the inside of the tube and iron flat. (see first photo)
Iron and topstitch strap on all 4 sides, pivoting at corners.
Fold the strap in half lengthwise, with the 2 ends lined up and directly on top of each other. Sew both ends to the wrong side of the bag near the top, about 1" below the top of the bag, centered on the inside edge opposite your bound buttonhole, backstitching and making sure the raw edges of the tube are enclosed. I find that sewing a rectangle works best. (The strap is sewn 1" below the top of the bag so that it is the same distance below the top edge as the buttonhole.) The last 2 photos show what it looks like on the inside of the bag once you have attached the strap.

Step 6: Pull Strap Through the Buttonhole to Form a Self-closure (3rd Trick)

Pull strap through the buttonhole to close the bag and wear on your wrist. No need for snaps, zippers or other hardware - the strap keeps the bag closed and you are ready to go! The front and back views of bag are shown in the middle 2 photos (seen notes on these photos).

Enjoy!