Intruders look for no, or few obstacles blocking quick exits. Fences prevent burglars from carrying away large items if the gates are locked. Gates should be locked at all times, even when your are home!
Ladders and tools should be stored in a garage or storage shed, and these areas should be locked.
Landscaping should also be designed to control access to your property. Proper barriers make the person with criminal intent feel uncomfortable as he or she approaches your home or business.