It's been nearly two years since the Defense Commissary Agency (DeCA) started their rewards card program, and I think it has really started working for people. One thing that has made a huge difference for me is using the mobile app. I love it!
The app was quick and easy to download. Once I worked out my password (always a challenge for me), it remains active on my phone. I open the app when we get to the commissary, and scroll through the available coupons. The interface is super-simple, with coupons moved to your card with one touch. You can view all the coupons you've "clipped" or all the coupons available. Even though I don't have great cell phone reception in my commissary, it only takes a moment to clip everything you'll need. When you get to the checkout, just scan your physical rewards card to have the coupons applied to your bill.
I've played with different ways to use the cards, and I find that the most effective system for me is to electronically "clip" every available coupon. (I might skip ones that I will never possibly use, like dog food.) It doesn't take any space to store them, and it takes literally moments to clip them. The computer figures out which items I've purchased, so it is no extra work at that end. It takes approximately 1-2 minutes to move every available coupon into my electronic coupon keeper, and I benefit from the savings on the items I actually buy.
There is one improvement I wish that the commissary rewards card would make: make my card's bar code available on my phone to be scanned by the cash register. This would mean that I wouldn't even have to carry my card. We've not lived in the US in a few years, but I hear rumor that some stores in the US do this and seems like a fabulous improvement to me.
If you haven't gotten a rewards card, or don't use the card you have, because it seemed like a hassle to go online and clip coupons, then the rewards card app for your smart phone is the solution to your problem. It is fast, it is simple, and it saves money.