There’s two ways to get comps and upgrades in Vegas casinos. The first way is to make sure you use your player’s card every time you gamble. Regardless of the game, every time you sit and gamble you’ll get points towards freebies and upgrades. If you play enough, you can cash them in for rewards. Most casinos will carry over these points from the last time you played. You can go a year or two and they’ll still be valid.
The other way to get comps and upgrades is to ask. If you’re very polite you can often get comps from the pit boss of the game you’re playing. They have the ability to give them out, and if you wait until nobody else is around you might get lucky. Don’t demand them, or talk about all the money you’ve been losing – just ask if he has any coupons.