At airports: Travelers should wait until they are just about to go through the scanner before putting anything valuable into the mouth of the X-ray equipment, such as a laptop or purse. That way their valuables won’t be sitting unattended on the other end where anyone can get to them. All travelers should buy small locks for carry-on bags, especially if taking overseas flights—someone could go through the bag while you sleep. Get to the baggage claim area as quickly as possible so that no one can take your checked luggage.
At hotels: Keep the TV on when leaving your room, and keep the bathroom door slightly open with the light on inside—then put the “Do Not Disturb” sign on your door. Hide anything valuable that you must leave in the room—for example, put a laptop computer inside a bag of dirty laundry.
What else to do: Put cash and loyalty cards in one wallet and credit cards and identification in another—if you are held up, give the thief the wallet with the cash and loyalty cards.
Source: George Hobica, founder, AirfareWatchdog.com, New York City.