They'll target a house they can get in and out of quickly, quietly and without being seen. And how do they choose that house? From the outside.

That's why your home's outward appearance can be your first line of defense against break-ins.

"What criminals see . . . is 'I can access this property because I perceive it to be vulnerable,' " said Terri Kelly, director of community outreach and support for the National Crime Prevention Council. Make your home appear risky for intruders and you greatly increase the chances they'll pass it by, she said.

The best news is that most exterior fixes are highly cost-effective, said Marc Rospert, executive director of the Ohio Crime Prevention Association. Rospert believes security investments such as alarm systems are fine, but "all these kinds of things can be done before you think about putting in an alarm," he said.

Landscaping is one of the first elements burglars consider when they're casing a house, said detective James Conley, a community relations and crime prevention specialist with the Akron, Ohio, police department. Specifically, "they're going to look to see if there's a place to hide," he said. Tall shrubs or dense trees that grow in front of windows or block the view of entry points provide the ideal cover for a thief to work, Conley said. He and the other security experts recommended trimming shrubs so they don't reach higher than window sills and keeping tall plants away from entrances. For a tree that grows close to a house, he said, keep the bottom branches trimmed about three feet off the ground, so the legs of a person standing behind it can be seen.

If you're planning some new landscaping work, consider positioning thorny or prickly plants directly under windows, Conley suggested. They make breaking into your house that much more uncomfortable -- and that much less appealing.

Before you select trees or shrubs, though, Kelly recommended taking their growth patterns into consideration. Those plants won't stay small forever, she said, so think about whether they'll eventually block the illumination of a lighting fixture or obscure the view.

It's important to keep the yard well-maintained, Rospert and Conley said -- grass mowed, shrubs trimmed, snow shoveled, toys and trash picked up. Rospert said that not only does that indicate that someone's around to do the work, it also signals to intruders that you care about your property, enough so that you've probably taken steps to protect it.

Lighting is another crucial contributor to a house's exterior security, the experts say. Burglars don't want to be seen, so they'll look for darkened doorways and shadowy back yards that will obscure their work. By removing the cover of darkness, you've taken away an incentive for them to choose your house.

Good lighting, however, doesn't have to involve investing in spotlights or motion sensors, Rospert said. "Before you do that, change the bulb on your porch light," he said.

Kelly recommended illuminating all the major entrances to a home, such as the front door, the back porch and the garage door. Usually fixtures are located in those spots, so use them.

Even interior lamps light the outside to some extent, Rospert noted. Discouraging a burglar from breaking in through your back window might be as simple as keeping a light on in that room.

If you don't want the bother of remembering to turn a light on in the evening and off in the morning, you can use a timer or install a fixture with a light sensor. Or just buy an inexpensive light-sensing socket that screws into a standard socket. Motion-detecting sockets are also available that turn standard fixtures into motion-sensing lights, which come on when someone approaches and turn off a set amount of time after the movement stops.

Motion detectors, however, are a matter of some debate among security experts. In the right setting, they can be a useful deterrent and alert a homeowner to an intruder's presence, Rospert said. But in a situation like his home in the country, where deer are continually approaching the house, or in a place where people or large dogs come and go frequently, a motion-sensor light will go on and off so often that "people might not pay much attention," he said. Or worse, they might get so annoyed that they turn it off.

If you do buy a motion-sensing light, do your homework, Conley said. Buy a good-quality light that will be triggered only by a significant presence, not by every raccoon or neighborhood cat.

Privacy fences are another feature that makes the safety experts wary. Solid stockade fences and dense hedges may shield you from the neighbors' prying eyes, but they'll also shield burglars from view, they pointed out. Consider whether a well-placed tree or small cluster of shrubs might do the job just as effectively, without blocking the view entirely. The sense of privacy that fences and hedges provide might be nice, "but I hope you have a guard dog," Conley said.

He was only partly joking. An alert dog is a great deterrent, he said, and so is the suggestion of one. If you don't have a dog, Conley suggested putting a dog dish outside the door and maybe a chain in the yard. A burglar who sees those clues isn't going to take the time to investigate whether a dog really lives there. He's going to leave.

Before you go to that length, though, make sure you're not making what the experts say is a common exterior security mistake: leaving the garage door open. "I can't tell you how many times people walk up the driveway and take things out of the garage," Rospert said.

It's also standard operating procedure among burglars to enter an unlocked garage and close the door, giving them complete privacy so they can take their time breaking into the house. That's why it's important to have a good lock on the service door between the house and the garage, and to use it, Rospert said.

Be careful not to give burglars other easy ways in, he said. Avoid storing extension ladders outside, and don't keep tall stacks of wood or other objects next to the house. Burglars might climb them to get in an upper window.

Some of the best exterior security options, however, are the ones that exist beyond the boundaries of your property. They're your neighbors.

"We all had that nosy neighbor growing up," Rospert said. "But I'll tell you what: She's a police officer's best friend, and she's also a neighborhood's best friend." She knows the people in the neighborhood, she knows their routines, and she knows when something's amiss, he said.

Even neighbors with less curiosity are likely to keep an eye out for the people they know and care about. So introduce yourselves to your neighbors, he suggested, and then make an effort to get to know them beyond the occasional wave as you're pulling out the driveway. Ask for their phone numbers. Offer to pick up their mail and newspapers when they're away, and ask them to do the same for you.

Consider that just a part of the whole security puzzle, Kelly said.

"No one strategy, no one piece of hardware, is going to keep people out of your house," she said.

But a little thoughtfulness and a series of good choices just might do the trick.