Not only is valet parking a long tradition at Las Vegas hotels, but free valet parking is ubiquitous (unlike most other places in the country). Every major and most minor hotels have valet parking: You simply pull into the front of the hotel (follow the signs to valet parking at the megaresorts), where your vehicle is parked by an attendant called a "valet."
Anyone can use valet parking. It doesn’t matter whether you're staying at the hotel where you're parking or not. You’re not required to have a hotel reservation, show a room key, or anything of the sort.
In fact, it's a quick and easy transaction. You simply pull up to the valet-parkers' area and exit the car, leaving the keys in the ignition; a valet will hand you a claim ticket and park your car in the valet lot.
When you're ready to retrieve your car, approach the valet booth or window and hand over your claim ticket. Depending on how big the hotel is (at the big joints, the valets have to cover some ground to get your car and return it to you) and how busy it is (15 people's cars will be arriving before yours), it'll take anywhere from two to twenty minutes for your car to show up.
When it does, it's customary for the driver of the car to hand the valet a tip. This is usually most convenient when the valet is exiting and the driver is entering the vehicle. The valet usually holds the door for the driver, poised and ready to stick out his paw for the green.
What's an appropriate tip? Five dollars is the norm these days, up three or four bucks from a bygone era. That's hardly free. But a tip's a tip; you can give as much or as little as you like. It's absolutely free if you don't mind stiffing a service person. If you have an expensive car and/or it's clear that you've received preferential service, a $10-$20 tip isn't uncommon. The tips are pooled, then split evenly among the valet staff.
On occasion, you might want to toke the valet who takes your car when you drive up. For example, if you're driving an expensive car or if you're only parking for a few minutes, and you want your car left up front (in other words, not parked in a garage or lot away from the porte cochere), you should talk to the valet beforehand and hand over a gratuity at that time.
Another time to tip a valet attendant when dropping off, rather than picking up, your car is if there's a sign that says, "Valet Parking Full." Valet parking is rarely full. It might be crowded, but these car jockeys can almost always squeeze another car in. Tell them you're staying there (and show a room key), or you have dinner reservations, or you're attending a wedding, or anything you can think of, and hand over some money. They'll take your car all right.
You can leave your car in valet parking as long as you like. One valet of our acquaintance claims that they don't start noticing long-term cars until the layer of dust covering them is at least a quarter-inch thick. It's rare, but sometimes the hotel has to try to track down the owner of a car that's been seemingly abandoned in valet parking.
Note that you valet park your car at your own risk. On the claim ticket you're given when you check in your car is a disclaimer, which always has some variation on the theme: The issuing business assumes no responsibility for lost, damaged, or stolen items in the car, or for damage to the car itself. Some even disavow any responsibility if your car is stolen while in the custody of the business. Be sure to read the fine print; the assignment of responsibility varies from property to property.
One time, our car was returned with a flat tire. The valets disappeared faster than we could say, "What happened?" No one knew anything. The supervisor read the fine-print disclaimer to us, then disappeared. And then there was no one else to talk to. The damage, both to the tire and rim (bent while the car was driven on the flat) was definitely on us.
Hang onto the claim ticket for dear life. Though you’ll eventually get your car back without a claim ticket, it’ll take a lot longer and can turn into a hassle.
Also, keep in mind that the ticket is the figurative equivalent of your car keys. If you lose your ticket and someone else picks it up and takes it to the valet window, all he has to do is toss the attendant a buck or two and drive away in your car.
Never leave anything of value in your car when you valet park. Though most valets, presumably, are scrupulously honest, why tempt them?
Also, never give the valet all your keys; leave only the ignition key in the ignition. If you’re a local, take your garage-door opener, registration, and proof of insurance. In our book The Battle for Las Vegas is the story of a gang of Las Vegas thieves (in the bad old days of the early 1980s) who paid off valet parkers to give them leads on locals out for the evening. The attendants would ask an innocent question: "How long are you planning on staying here tonight?" If it was a number of hours, the thieves drove off in the locals own car, pulled into the garage, and robbed the house at their leisure. Then they’d return the car and no one would be any wiser.
Also note, especially in this questioner’s case (since you say that you’ll be renting a car in Las Vegas), that it’s risky to valet park rental cars. When renting a car, you must designate all the drivers of the car. If anything happens to a rental car while it’s being valet parked, the agency can and will deny coverage, even if you pay for insurance through the car-rental company.
Bottom line: Virtually 100% of the time, your valet-parked car is returned intact and untouched. But you need to know what can happen in order to take precautions against the possibility of it.