Slip your hotel concierge a $20...
Ah yes, good old bribery. The “$20 trick” is a common piece of Vegas lore that has no reason not to apply at any hotel. Rumor stands, slip a $20 to the desk clerk checking you in and straight-up ask if there are any room upgrades or other deals available. It will go one of three ways: You’ll get an upgrade, you’ll get your $20 back, or you’ll get a “nope, but thanks.”
Tip. Tip everyone, and tip well.
Tip your housekeeping staff, your bellboys, your everyone. If you’re a return customer or have to extend your trip, it’ll pay off. And if a hotel or restaurant does end up with a better room or table -- who are they going to give it to? That crazy old coot in room 7 who never tips? No, silly. It’s you!
Don't ask for things when other guests or customers are around
If possible, don’t inquire about free stuff when other guests or customers can hear you. The hotel clerk, or whoever, knows that elementary school birthday party rules will apply: If they give one to you, they’ll have to give one to everybody.
Always give feedback -- both good and bad
Being honest about your experience requires you to be vocal about it. I don’t think I’m alone in having the instinct to just smile silently and trust that those in charge will know what I’m experiencing and compensate me accordingly. If your service is great, say so. If your hotel room has a funky smell or some doohickey on your flight is broken, definitely say so. Maybe a better alternative is available, or maybe, to make sure you’re a happy customer, the provider will go above and beyond. Complimentary drinks, baby.