In both the manosphere and real life, I've heard of men trying desperately to sleep with a waitress they met at a restaurant or bar. I've worked in the service industry for several years, so for those who you who want to sleep with the waitress who served you a burger or rum and Coke, here's my advice on how to sleep with them:
Get a job as a server, bartender, barback, host, or busser, and hook up with girl(s) you work with.
No, seriously. If you are a customer, you have no chance of sleeping with a female server or bartender.
Yes, the cute, young, blonde server or bartender may be giving you so-called "indications of interest," but these are almost certainly false and meant to encourage you to tip more. The average restaurant or bar, after 9:00, is filled with couples and a 5:1 single male to female ratio. The women who serve you food and drink flirt with you, yes, but they do so in order to turn a 15% tip into a 50% tip.
In my years in the restaurant/bar industry, I have never once met a female bartender or server who has slept with a customer. But, I've known dozens who have slept with their coworkers
Yes, what I'm saying is that even though your cute server may act flirty with you, once you tab out and leave her $10 on a $20 tab, she'll end up going home with the 16 year old busboy before she goes home with you.
I've also noticed that male servers and bartenders are much more likely to sleep with customers. I remember at one place I worked, the managers assigned a male to work cocktail on a weekend night. He ended up netting several numbers. Most male servers and (especially) bartenders I've known have slept with customers, but as I've mentioned, I've never met a female server or bartender who has. When female servers get numbers on credit card receipts, they pocket the tip and throw away the number, but if a guy gets a nice tip and number from a cute girl, he will keep both.
So, wannabe PUAs, if you want to add a waitress to your belt notch count, instead of wasting money at a bar and tipping your waitress 50%+ in hopes that she will reward you with a number, get a job at a bar or restaurant. You'll end up having a lot more success.