shopping trip fail

Last night I attempted to plan a small shopping trip to CVS using the coupon circular I had gotten in last weeks paper (which includes symbols to tell you which items have coupons available in recent Sunday papers ) and online resources. I search for online blogs that post weekly deals and tell you which coupons to use on which items. I encountered a ton of problems :

1. store sales and the coupons available vary from region to region, state to state and store to store so while online sources can be helpful they don't match up where I live
2. coupons needed to get current deals might have come from Sunday papers that came out weeks ago
3. printable online coupons have a limit to how many times they can be printed and run out very quickly for the big deals
4. to get the best deals you need more that one copy of the same coupon (by one get one free sale using two coupons, one for each item)
5. products with the best sales go out of stock fast
6. one missing item or miss calculation can throw off your whole trip

so with all that I decided to hold off on the shopping until I had a better handle on how to plan a successful trip. Hopefully  my friend will get me in touch with his mom soon so I can ask her about how she plans her "extreme" couponing trips.