NEW YORK (CNN/Money) - Once again, mass transit is the target of another terrorist attack in London.

Experts say that there isn't much you can do to avoid a terrorist attack, but in today's 5 Tips we're going to tell you how you can be more prepared before boarding your bus, your train or your subway.

Put yourself in the terrorists' shoes. They're scared and nervous, says David Katz of security consulting company Global Security Group.

They will look out of place because they're so afraid of not fitting in. Watch their eyes. Potential terrorists may appear shifty, jittery and sweaty. A potential terrorist may wear unusually heavy clothes in the summer to conceal a weapon or hide a backpack. In addition, they may rub or fuss with their clothes.

"Someone who is hiding something is usually paranoid that it's showing too much, or maybe not enough," says Katz.

Bombers also may mumble to themselves, or pray quietly. It's a way to talk themselves into the task at hand. Be aware of people who look as if they are surveilling a site. Take note of anyone who takes an unusual interest in security measures, like guard barriers or security cameras.

A potential terrorist may also take a keen interest a specific building. They may have sketching items like a pen and a notebook, or a camera. Any suspicious activity or person should be reported to authorities.

David Katz has been face-to-face with terrorists. He has taught surveillance to federal agents. He is in charge of protecting people in emergency situations.

And every time he gets on the subway on his way to work, he scans the floor. He's looking for out-of-place or abandoned bags. "One time," he recalls, "I really made a ruckus and began asking passengers who it belonged to."

Katz says you have to take note of empty spaces. Reporting a suspicious package is for your own protection too. Katz feels better when he is on a train or a subway because at least passengers are checked.

"You don't see too many police officers standing at a bus stop," he says. "Anyone can get on a bus."

If you plan on traveling by bus, train or subway, don't show up early. People should always be concerned about crowded situations, says Kelly McCann, a Counterterrorism Specialist at Kroll Associates.

"You should be extra cautious near bus stops and subway platforms," he advises. "The shorter amount of time you can spend at these locations the better."

The best rule of thumb here is to arrive late and leave early. If you must stay at a platform, then stay away from garbage receptacles says Katz. You don't want to be near anything that could be concealing a weapon or a bookbag.

Stay away from garbage receptacles or benches where packages and bags can be stowed without notice. You may also choose to stand closer to authorities. If you see policemen, watch their gaze, Katz recommends. They should be looking at people's eyes and hands.

Get an escape hood. These hoods let people escape quickly from a place where there is smoke. Some hoods protect your eyes and lungs against chemical and biological agents. Escape hoods range in price from $40 to $180 dollars. Check out www.saferamerica.com or call 1-866-SAFER-99.

It's always a good idea to carry a flashlight. You can buy little key chain flashlights that have an LED light. And you should also think about investing in a pocketknife.

The Department of Homeland Security advises that people have a whistle and moist towelettes for sanitation. Have phone numbers written down and always keep some cash on hand. There's no telling what the electricity situation will be like in case of an emergency. For more information on security precautions you can take, go to www.ready.gov.

Know how to leave. This is something that you need to consider before getting on any kind of mass transit or station platform. When chaos breaks out, you won't have much time at all to figure out which is the closest exit.

Take note of where cabs tend to convene. In case of an explosion where the area is filled with smoke, people should get down on the ground and crawl toward the nearest exit. If possible, use the back of your hand to feel the upper, lower, and middle parts of closed doors. If the doors are hot, you have to find another exit.

For your own peace of mind, have a family plan. Howard Safir, the former New York City Police Commissioner and partner at security consulting firm SafirRosetti says families should also talk about a meeting spot in case of an emergency or terrorist attack.

Gerri Willis is a personal finance editor for CNN Business News and the host for Open House. E-mail comments to 5tips@cnn.com.