Start with the on-page 'Clip Coupon' checkbox — it's applied automatically at checkout.
Add a seller promo code in the gift card/promo field before placing your order.
Lightning deals lock in a lower base price; coupons stack on top when the seller allows it.
Subscribe & Save can add 5–15% but sometimes blocks promo codes — test both paths.
Always verify the final price on the checkout screen before paying.