L.P.
I've never used a service, so I don't have any information about that part of your question.
What I do is, on Sundays, I go out and but a Sunday newspaper (or 2) IF there are coupons in them. Every once in a while, there aren't any in there.
When I get the sale flyers for the grocery stores weekly sales (usually Thursdays), I make a list of sale items I'm interested in. Then, I go through my coupons and try to match coupons with sales, if possible.
The best weeks are the weeks that have 3 or 4 coupons printed in the flyer that double one of your $1 coupons. I save $6 to $8 right off the bat those weeks.
One week for example, Green Giant frozen boxed veggies were on sale for $1 each (which is more than 50% off the regular price). I had a coupon for $1 off of three. I also had one of those coupons that doubled it, so I got 3 boxes of veggies for $1 !! They would have normally cost me over $6. Celestial Seasonings Tea was on sale for $2.50. Again, I had a $1 off coupon, which was doubled, so I got the tea for 50 cents. Colgate toothpaste was on sale for something like $1.88) -same deal- so I got it free :D
I typically save more than $80 a week with sales and coupons.
Another thing I do is, once I've found out which meats are on sale that week, I make a meal plan for the week, and try to get everything in 2 trips (because I shop for the sale items @ 2 different stores). I'm a SAHM, and we have 4 children- we were spending tons of money each week before I started doing this. I actually enjoy it because it feels like a challenge to see how much I can get for the lowest price possible. It helps to increase our standard of living because I get so much more by sales/ coupons.
Another thing that helps is I go Thurs. or Fri. evening after supper without the kids :) So much easier that way. There are only a handful of other shoppers there, and I can take my time without any, "oh mommy, can you please, please buy this?" so I wind up spending less that way too.