I made this for my Rainbow Mini Swap partner a few weeks ago. These little cubes are super easy to put together and very useful as a thread catcher or handy for holding just about anything. I start with two squares of fabric approximately 12.5" square and sew right sides together along three sides. Turn right side out and press. Insert a piece of stiff interfacing (I used Pel-Tex) that is just slightly smaller than the finished dimensions of your fabric square. Fold in the unfinished edges and press. Top stitch all the way around close to edge and make sure you catch the previously un-sewn edge.
Then quilt as desired. I used Leah Day Concentric Circles. The thread is Aurifil 28 weight and really looks fabulous! I am using m y Juki TL2010Q for FMQ.
After quilting fold the square in half and sew a seam starting about 3" up from the fold across to the bottom fold creating a triangle. Do this on the right and left sides and then re-fold the square in the opposite direction to make the seams on the other two sides. This will be done with your square folded so that the fabric that will end up on the outside is to the inside of the fold.
The final step is to fold down the flaps and add a button if you choose. I used vintage MOP (mother of pearl) buttons I scored on e-bay a few months ago.
And there you have it! I bet the instructions for sewing the corners are a bit confusing without pictures so I will try to take some next I make one of these.