Three settings make a coupon work only on bigger orders. You can use any of them on their own, or together:
Minimum Order Bottle Quantity: the number of bottles the whole order must have.
Minimum Required Product Quantity: the number of the coupon's required products the order must have. This only appears once you've chosen products in Required Products in Order.
Minimum Order Total (Excluding Shipping): the amount the products must add up to.
Leave Minimum Order Bottle Quantity and Minimum Order Total at 0 for no minimum. Minimum Required Product Quantity only applies when the coupon has required products.
What Minimum Order Bottle Quantity counts
All the bottles in the cart, whichever wines they are. The screen describes it as "any bottle products (including those in mixes)".
A mixed pack counts as the bottles in it. A mixed six pack counts as 6.
Products that aren't wine, such as T-shirts or corkscrews, don't count.
What Minimum Required Product Quantity counts
Only the products in Required Products in Order, added up together. Other products in the cart don't count.
A mixed pack counts as the bottles in it.
It must be 1 or more. See How to make a coupon that only works with certain products
What Minimum Order Total counts
The products in the cart, not shipping.
Prices after the customer's other discounts, such as their club discount or a 6-bottle price, but before this coupon's discount.
Products the coupon makes free still count. For example, with a $150 minimum and a free corkscrew, a customer with $135 of wine plus a $25 corkscrew meets the minimum, and then gets the corkscrew free.
Example: minimum $170. Wine at $180: the coupon works. A club member whose $180 of wine comes to $167.40 after their club discount: the coupon doesn't work.
Using them together
When a coupon has more than one minimum, the order must meet all of them. For example, "buy any 12 bottles, including at least 6 Shiraz, spending at least $300":
Required Products in Order: the Shiraz
Minimum Required Product Quantity: 6
Minimum Order Bottle Quantity: 12
Minimum Order Total: 300
With 6 Shiraz and 6 other bottles the coupon works, as long as the products add up to $300. With 6 Shiraz and 5 other bottles, the order is short of 12 bottles. With 5 Shiraz and 7 other bottles, the order is short of 6 Shiraz.
Steps
Go to Settings > Coupons and open the coupon, or click + Add Coupon.
In Minimum Order Bottle Quantity, enter the number of bottles, for example 12.
To require certain products, click Edit product preference next to Required Products in Order, choose the products and click Set Products. Then enter the number in Minimum Required Product Quantity, for example 6.
In Minimum Order Total, enter the amount, for example 300.
Click Save.
What happens next
If the order doesn't meet a minimum, the customer sees a message:
"A minimum of 12 bottles is required for this coupon.": not enough bottles.
"A minimum of 6 qualifying products is required for this coupon.": not enough of the required products.
"This coupon is not applicable to any of the qualifying products.": none of the required products is in the cart.
"A minimum order total of 300.00 is required for this coupon.": the products don't add up to the minimum.
If the coupon is set to Auto apply, it applies by itself as soon as the order meets every minimum, with no message before that.
Troubleshooting
The customer has 12 items but the coupon says it needs 12 bottles: some items are merchandise, which doesn't count.
The order has 12 bottles but the coupon says it needs 6 qualifying products: not enough of the bottles are the required products.
A club member's order is over the minimum total but the coupon fails: Minimum Order Total uses the price after the club discount.
Every minimum is met but there's no discount: the customer already has a cheaper price on those products, such as a 6-bottle price. See Why is a coupon code not working?