When selecting your shoulder cord, be sure to review your uniform regulations. Each uniformed service has specific regulations governing the wear of awards and decorations. Next, you want to determine your uniform epaulette style, if any. If your uniform shirt or jacket has a button-down epaulette, you'll want to choose a cord with a button loop. If your uniform does not have epaulettes or you wish to wear your cord aligned to the outside of your shoulder, select a shoulder cord with a pin attachment.
For cords with button-loop attachments, just unbutton the epaulette, secure the cord's loop around the button and refasten the epaulette as normal. For shoulder cords with a pin attachment, be sure to carefully align the pin on top of the shoulder just inside the outside edge where your sleeve begins. Secure the cord, making sure that most of the pin has been pushed through the material for a secure hold. If your shoulder cord has additional accoutrements or accessories, consult your uniformed service's regulations for proper wear. Then attach or drape these accessories as described by your manual.
If you're participating in a drill or other ceremonies that require movement, you may want to secure the bottom of your cord under your sleeve to keep it in place. To do this, simply use an average safety pin, hiding the majority of the pin in the lower loops of the cord material, to attach the cord to the side of your shirt or jacket. Be sure to leave yourself enough room to comfortably move your arm and shoulder without pulling the cord tight.