It's so rare to find a physical coupon for what I need that I've given up on them. I do a quick check for coupon codes whenever I shop online at somewhere other than Amazon though.
When someone tries to hand me a massive 3' long receipt I like to pretend I have no concept of what is going on and won't even reach for it. I'll just give a blank slack jawed stare until they awkwardly ask if I want the receipt and I'll silently shake my head no until they tell me to have a nice day as a signal for me to leave.