Back in my day, circa the 1950s, U. S. Girl Scout badges were 1 1/2" in diameter. Most of them had a green background and a green border, with colored embroidery for a design. Today, there's no need to limit ourselves. We can make our badges any size, shape, and color that we want. I chose purple for my writers' badges to represent purple prose.
I'm assuming a familiarity with sewing stuff. If you've never picked up a needle, but are suddenly inspired to sew a badge, get in touch with me, and I'll walk you through the basics.
Badges look better if quilted, so we'll need a top and bottom layer of fabric and some quilt batting in the middle.
Draw the badge outline in pencil on the top layer of fabric. Stack top layer, batting, and bottom layer. Use a satin stitch to work the outline through all three layers.
The easiest way to sew a badge is to let patterned fabric do all the work. For example, this fabric might represent the "Where Do You Get Your Ideas" badge.
We can also use rubber stamps, drawing, or embellishment techniques like beading to create the central design.
If we have access to a pre-programmable embroidery machine, the sky is the limit. If you we can fit it in the badge outline, we can turn it into a badge.
After the badge is complete, cut out carefully around the outside of the satin stitch. I like to apply Fray Check around the cut edge.