If your holiday plans include a trip, there's something you should think about besides trimming the tree - crime.

A survey by American Express shows that the holiday season is second only to the summer vacation period in both the number of Americans traveling and the number of crimes that occur in U.S. airports.

The survey reported that most airport crimes are crimes of opportunity; hurrying makes us more vulnerable as targets of crime; and thieves are using more sophisticated techniques such as extraction/distraction to separate us from our valuables.

"This survey of airport security managers, who frequently witness crimes committed against travelers, points to the fact that travelers need to be more aware of their susceptibility to the actions of airport pickpockets and thieves," said Ron Glover, president of American Express Travelers Cheque Group.

"With the overall increase in thefts and pickpocketing in high traffic areas, travelers can protect themselves by taking a few simple precautions."

- Never leave bags unattended. Push a baggage cart in front of you instead of pulling it, to make sure your belongings are in plain sight.

- Men should never carry their wallets in their back pockets; use the inside breast pocket of your coat. Women should carry handbags with the flap turned towards the body and against the hip, or in front where they can see it. The handbag should never be allowed to slide in back.

- Carry cash, travelers checks, passports, tickets, charge cards and other valuables in different places. If everything is carried together, the chance is everything will be stolen.

- Escalators, doorways, baggage claim areas, phone banks, check-in lines and bathrooms are key areas where a thief can work undetected. Airport security managers recommend being extra wary and keep a watchful eye on your belongings in such places.

"Distraction/extraction" is a favorite ploy of many airport con artists. A thief might create a distraction by dropping the contents of a purse or bag in front of a traveler. As the traveler bends down to help, an accomplice comes up from behind and walks away with the traveler's luggage.

In other cases, a traveler may leave a bag or briefcase unattended while buying a cup of coffee or a newspaper. The thief can simply pick it up and walk away.

Foreign travelers, older travelers and affluent-looking travelers are the most attractive targets, the survey reported. Security managers recommended "dressing down" so travelers will not draw too much attention to themselves.

American Express offers a free booklet "Last Minute Getaway Cheque List" that includes a list of things to do before departure and a budget guide for vacation expenses. Send a stamped, self-addressed business-sized envelope to: Elizabeth Jones, American Express Travelers Cheques, World Financial Center, New York, NY 10285-3700.