Before you start stitching, let's look at where the badges go. Luckily, the Girl Scouts of America have put together some easy charts to help you out: Insignia Placement. This is very important, because misplaced insignia can crowd out those you will need to add later. It's no fun ripping stitches and restitching patches.
Along with the placement chart, you'll need a needle and thread, or a sewing machine. Let's take a look at hand stitching.