Start by filling your shopping cart on PencilBoxShop.com with desired items. Navigate to a reliable coupon site to fetch a suitable PencilBoxShop promo code. Click 'Get Code' to copy it. Proceed back to your cart on PencilBoxShop, fill out necessary details, and look for the 'Enter Promo code/Discount code' section. Enter the code for a reduced price on your chosen items. If the promo code is compatible, it might be applied directly during checkout for a seamless experience.