Jenny Martin, the blogger behind Southernsavers.com, jokes you have to think about CVS being its own world with its own currency. That's because a lot of times when there are qualifying purchases, you get back extra bucks or store credit.
So, if you use coupons on top of things that qualify for extra bucks, you can really save a lot of money.
Another thing – a lot of people do multiple transactions at CVS. The clerks are used to it, just tell them that's what you're doing. And, if there is line, it might be more courteous if you let people move ahead of you if they have just one or two things to buy.