Park a car in your driveway, locked, without valuables and especially without the garage door opener. IF you have a new car and use the integrated button to open your garage than simply buy a $5 sliding bolt lock at the hardware store and install it inside your garage. This way if someone does break into your car, the bolt will prevent them from opening the garage door too.
Put up home security signs, or better yet get a home security system. Cameras are much more affordable these days and can be installed on the outside of your home as well.
Dog or not, get a supersize dog toy from Walmart or wherever you shop. Beat it up and get it nice and dirty. Put this between your house and the most public access way. A chain works as well
Cover up or put away valuables - tools, toys, tractors, etc... dont leave them laying around your yard. If you cant put them away inside or store them than at least cover them up out of sight.
If you are at home during the day, take 5 minutes every half an hour to look outside. It will give you a break from whatever you are doing and allow you to be more aware of whats going on.
Keep your home hedges and bushes trimmed and below your windows. Big bushes make an easy place to hide for anyone snooping around.
Create a neighborhood watch with other community members. Mind you this simply means being vigilant as a group and sharing information from day to day, not being a security guard or looking for trouble.
Keep your doors locked at all times. This means your car and your house. If you have to go get the mail, simply shut your door and walk to the mail box, but if you need to run down the street, lock up the house. Windows too!
Technology can also be your friend if used properly. Sensors, timers, monitors and remote controlled lighting, doors etc... can be useful so long as you have a strong password protected wifi and a strong password on your device
Keeping your entry and exit areas well lit at night is essential, so although the bug build up may be a pain to clean, it's better safe than sorry.
Finally no amount of tips will help in the event you find someone at your house so make a plan for what you would do if you were home and someone knocked, someone walked in your backyard or even tried to get in. Have a plan to get somewhere safe, secure and with a phone to call for help. Don't try to take matters into your own hands unless a life depends on it.