I don't.
It's a weakness in my game. I can't just let it slide. On occasion I can grit my teeth and tolerate it. But sometimes, they just won't shut up, they just won't stop harassing me, and I always wind up saying something.
I had a situation where I split tens against a 6 with a max bet out and this ploppy started tearing into me telling me how stupid I was. "I hope you lose, jackass" were his exact words. When the first 2 cards out of the shoe were "Ten" and "five", he was even more incensed that I "stopped the dealer" from getting 21 and I wound up splitting 4 ways with a doubled soft 21. The dealer bust.
I turned to this guy and said "Do you have something to say right now?" No answer. "Huh? Do you, jackass?"
"You're an idiot. You screwed up the rest of the shoe."
While this is going on, the ploppy is busy being dealt a blackjack, and the dealer busts again. It's the end of the shoe.
"Yeah, I screwed it up so much that we won again!"
"Well, you're still an idiot."
"Yup. I'm an idiot. Stupid idiot me. I'm so stupid, it'll take me at least 10 seconds to count ALL THIS EXTRA MONEY I WON because of my idiot plays."
With that I stormed off to the cage and calmed down over a nice meal.
While I don't recommend doing this, I *WILL* say that after I was done chewing this guy out, I felt *soooooo* good. :)
M.