Once you have hand-sewn in your sweatband, and attached your crown to the brim collar, and you are ready to hand sew your ribbon round the outside of the crown, make sure the seam match is perfect. Use this tip. Take a pin and put it through your centre back of your ribbon, brim collar and crown so it comes out the other side. Gently feed the ribbon, going around the outside of your hat, down to meet the bottom of the crown disguising the join. Adjust the ribbon so that your seam lays in line with the pin. It's all about the small details that make it seamless.