There are a few common tricks that burglars will use to get access to your home through your garage. The key to stopping this from happening is to be aware of what sorts of tricks they use and how to counter them.
Emergency Release Tricks
Using the emergency garage door release is a favored practice among thieves. What they will do is get a coat hanger or other similar device and slip it between the cracks that separate the door from the wall. Since emergency release switches tend to all be in the same area on doors, they will often be able to grab the release after a few tries, and then open your door and get inside.
The key is to make sure you protect against this approach by using a zip tie to lock the disengaging arm on your auto door opener. This will make it impossible for a thief with a coat hanger to make the release engage. However, if you have an actual emergency and need to get out of your garage, you can still pull on the release hard enough to just break the ties.
The idea of an absolutely impenetrable door is largely a myth. If a thief sees something valuable enough in your garage door, they can usually smash their way in. The key is to make it so that they can't even see anything to begin with by frosting over the windows. If you get them tinted so that they are dark, people won't' be able to window shop by going by your garage.
Thieves may rely on having a way of gaining access that creates minimal sound, and since you aren't in your garage all the time, this can be a serious enough problem that deterrence can often be the best solution. You don't have to adapt to a burglary that is never attempted.
Weak Point Attacks
Another common approach is to go after weak parts to your door cause by corrosion. Any hole in the front of the door could potentially be used to gain access to the mechanics of the door, allowing for entry. Any corrosion or damage to locks, hinges, or the frame itself could pose a threat if a thief can just break it easily due to rust or some other issue.
Putting yourself in the shoes of a potential thief will go a long way to helping you prevent break-ins. This way, you can shore up what you would determine to be the most likely attack points on your door. To learn more, contact a commercial door company like Steel Doors.