I avoid things like not now, or maybe later. I also avoid the "I'm waiting for someone else" excuse when I'm not interested, even if I do happen to be waiting for another dancer. I don't want to give her the impression my lack of interest is temporary or circumstantial when that's not the case. Her being fat, ugly, smelly, mean, arrogant, entitled, or whatever made me disinterested is a persistent condition. There's no need to repeat the interaction, I'm still not gonna be interested. If you send mixed signals, she's likely to get bolder on subsequent tries and you'll find yourself having to be a dick.
I don't do rejection tips. I've caved before, but as should be obvious it just leads to more bad behavior. She'll be right back 20 minutes later, or the next time I come to the club. All the other bottom tier girls see it works and they'll all take their turn too. You'll attract more and more desperate, lazy, and or unattractive strippers and they'll get bolder and more entitled with every interaction.
Sure, it's only a few bucks and a few minutes each but every dollar in her purse is one that doesn't go into a more deserving stripper's bag and every minute I spend with an ugly bitch is one I don't get to spend with a cutie. Not only does it erode my experience for each individual visit, over the long term I feel like I'm contributing to more ugly bitches and less hot ones in the club making the next visit just a little shittier for me and my fellow clubbers.