All you'll need is some white felt, scrap fabric that resembles the colors of our flag, and a dowel rod... bamboo skewer or even a stick could work.
First, cut the red and white fabric in a rectangle, and the blue and white fabric in a square. You'll also want to cut two pieces of felt the same size that you cut the red and white fabric.
Next, you'll place the blue square in the corner of the rectangle fabric and sew (see photo as to which edges you'll sew)... or you can glue this fabric on to the other.
Then, you'll take your flag, and place them on the white rectangle felt pieces. You'll double up the felt, so that it'll make a sandwich, in which you'll slide in the dowel rod, and sew. Remove the dowel rod before sewing. I "eye balled" the width of the dowel rod, so you know, where NOT to sew... but you can even place the dowel rod in place, and pin it, before removing the rod, so you have the exact width.
Last, slide the dowel rod into place.
They're a little wonky... but I love that about them. Stick them on a cake, add them to a plant for a host/hostess gift to the picnic you're going to, or just let your kids have fun waving them around.