Install good locks on all doors and windows. Check to ensure that all doors and first level windows are securely locked at night. Also, a rod or stick that fits snugly in the track of your windows or sliding glass doors will greatly increase window and door security. Leave outdoor lights illuminated even after you retire to bed. Also, motion sensor lights are inexpensive, easy to install, and effective in helping to scare away prowlers.
Criminals tend to avoid well-lit places.
Remove all obstructions, such as shrubbery, that block the view of your windows and doors. Make sure that windows are equipped with blinds or drapes, and keep them closed at night, especially in bedrooms and bathrooms. Keep an inventory of your valuables and electronic equipment so you will know immediately if something is missing. Include photographs of jewels and serial numbers of other costly items. Etch your Social Security Number on items, when possible.