Search '[store] promo code' every time
A hit is typically 10-20% off; misses cost thirty seconds.
Let code-testing extensions try the list
Auto-apply extensions test known codes at checkout so you don't tab-juggle.
Abandon the cart overnight
Logged-in carts left idle frequently trigger a discount email by morning.
Sign up, buy, unsubscribe
The welcome-email 10-15% is a one-time toll refund. Take it, then guard the inbox.