I just say, "No."
My better half has been trying to teach me to say, "No, thank you," but that hasn't been working out too well for her. She says I'm too mean/intimidating.
People hate it when you just tell them, "No." In fact, it most often really disturbs them and/or pisses them off...but I find it to be most effective.
For instance, when walking through Sky Harbor Airport Terminal 4 and I'm approached by one those shills that works for a credit card company with the pitch, "Come here" - while waving me over - "and I'll show you how you can receive a free round trip anywhere in the continental U.S.", it's at about the point they reach "show you", that I respond.
"No."
Not, "No, thank you," because that doesn't work, they continue their hard sell, especially if you say it politely. I happen to say it like I mean it, like FUCK YOU, like I want her and her whole family's skulls to clean and donate to Bubba's wall.
She gave her co-worker the look people usually give their co-workers after I respond, "No" - the raised eyebrows, the shrugged shoulders, the "What did I so wrong?" hurt look...all mixed with "Wow, what a dick!"
You too are saying, "Wow, Un's a dick!"
Am I a dick? "No."
Yes, of course you want proof, why wouldn't you?
For instance, I don't tell Girl Scouts outside the local grocery store selling their cookies "No." I buy them and then donate them to an organization that will ship them to troops overseas. In fact, I think they see a sucker coming as I'm suddenly rifling through my wallet for $40.
After that, if I happen to run into a gaggle of Girl Scouts/their mothers - and I always do, I respond with, "No, thank you."
It's okay to say No...right?