A high class escort will pursue a healthy lifestyle and will therefore usually not smoke, only drink within moderation and never use drugs. 

If the high class escort is a smoker, she will refrain from smoking before and during a booking. If the escort is a non-smoker, she is usually tolerant towards clients who desire to smoke. If you decide to smoke a cigarette during the booking, but the escort is a non smoker, be a gentleman and brush your teeth after taking a cigarette.

Most high class escorts are light social drinkers. This means they will enjoy a glass of fine wine or champagne during the booking, but no more than that. She prefers that you do not consume a lot of alcohol before or during your time together. Alcohol is a depressant and will not benefit your performance in the bedroom.

Using drugs before or during the booking, including (legal) soft drugs, is a definite no-go. Your high class escort would like to keep it a good, clean fun and therefore leave the booking if you are under the influence of drugs. The reason for it is both safety as well as comfort. Drugs can make a client act different from his normal gentlemanly behavior, which can be dangerous to the escort. In addition to potential danger, it is really no fun to be with a drugged out client.