Couponing at Dollar General

I haven't done a lot of couponing at Dollar General, but I have done enough and heard enough to know that they are not always real coupon friendly.  The actual concept of couponing at Dollar General is pretty straight forward, match a sale with an available coupon, but the methods are sometimes not so easy.  If you have a coupon that requires a multiple purchase such as $1.00/3, have them ring up 3, ring up the coupon, ring up the next 3, ring up the coupon, ring up the next 3...you're getting the picture here.  I am thinking back to this past Thanksgiving when they had Libby's canned vegetables on sale for 45c per can, and I had $1.00/3 coupons that I had gotten from ebay.  I had not realized this little nuance prior to this, so I had them ring up all my veggies, then handed over the coupons.  They came up with a million reasons why the coupons couldn't be accepted, and none of them was the "limit one per purchase" thing.  Finally the manager came up with the ring 3, ring coupon idea.  It worked like a charm...no further register problems.  From one of my friends on FB, I have heard that sometimes it just works best to always have them ring the coupon immediately after the product, you end up with a lot less headaches this way, and I think I may have to agree with this.  Dollar General doesn't always have an ad, and I rarely find a great deal even when they do, but I always at least look. Their ads come inside the coupon inserts of your Sunday paper.