Publix and Kroger will automatically double coupons that are 50 cents or under. Some Publixs are getting stricter about printable coupons which state Do Not Double, but it just depends on the Publix you go to and their policy. The one I go to on Pleasant Hill and Club will double all coupons regardless. Ingles will double three coupons per every $10 you spend. They also will not let you use more than two of the same internet coupon, and will not double more than two of the same coupon. No drugstores, Target, or Walmart will double any coupons.
Publix is the only store that I know of in my area that will accept competitors coupons. Yet again, this one is depending on your particular Publix on who they consider competitors. My Publix will accept Target, Rite Aid, CVS, Kroger, Ingles, and Walgreens coupons. If your Publix will not accept Walgreens Register Rewards try to talk to a manager since they do say manufacture's coupon on the top.
The sales are usually on a cycle of six-weeks. So, when things go on sale for rock-bottom prices and I can combine it with a coupon, I stock up for what my family will eat for six weeks until the item goes on sale again. I have noticed that not everything is a six-week cycle though. New York frozen bread is longer, chicken at Publix, Log Cabin syrup, etc. Those are just some of the ones I've noticed being longer than every six weeks. That way, you don't run out of items before it goes on sale again and you have to pay full price for an item.
Buy items when they are on sale for an awesome price and combine a coupon with that to get the greatest savings.
Grocery Stores in the South:
Except for in Florida, you do not need to purchase two items on a buy one get one free sale. Each item will be half off instead. This does not apply to drugstores however.
SS: Smartsource, coupon insert found in Sunday's paper
RP: Redplum, coupon insert found in Sunday's paper
All You: Magazine found in Walmart, or you can order it online, has tons of coupons inside
ECB: Extra Care Bucks, CVS program
SCR: Single Check Rebate, Rite Aid program