Using them right now. I prefer to do as few coupons as possible. But the few i do are targeted for what market i want to reach.
If you want to go for the single person, something around $8 to $12 works for my area. Families or large orders i shoot for $15 to $20 coupons.
As i have said in other threads on coupons tho, my discount is only 10 to 20% off my menu price. For the last year i have dropped as many of the single person type coupons as i could and i focus mainly on the larger orders.
Edit: But the type of coupons i use, Family deal (2 pizzas, cb 2ltr) Double ups (2 pizzas), pizza and wings, pizza and salad, and my carryout deals.