Need Your Input!

I had an mini-issue at Walmart today when I presented the $2 off KY and the $3 off KY printable coupons (remember those from a couple weeks ago?).  Obviously, I had two of the $2.62 KY products and the cashier handed the second coupon back to me and said he the coupon would only allow me to use one coupon and not both.  First, I thought he meant I didn't have two items, then I realized the register had beeped and he had read the "Limit one coupon per purchase" notation on the bottom of the coupon.  I asked him to hand me back the coupon, I read the fine print just to sure, and explained that "per purchase" is "per item".  He rescanned it and it went through without a hitch, go figure. 

The actual error message from the register was:  The coupon you are attempting to use does not match the items that were sold.  I think it was probably referring to one of the two trial size items I had purchased and used a coupon for and not the KY.

So, here's where I need your input.  I want to put together a "Quick Facts to Couponing".  Maybe something like a top ten list a la Letterman, but devoted to coupon usage instead of funny topics.  I want it to be something we can all hand over when we have these little situations.  Can't wait to hear your suggestions!

Thanks again, and happy couponing!
--The Hopkins County Couponer (6/17/2011)