Where does everyone get their Coupons?

I have found a couple of websites to get some coupons, but I read all the time on the Internet where people don't pay hardly anything for their groceries. How the heck do they do that? Either they are better shoppers than me or something. There must be a secret to it because I haven't figured it out. If anyone could give me some tips of where to look or how to do it I would be forever grateful. I would just like to be a someone who could do this too.