If you can't afford a security system, there are a lot of little things you can do to make your home more secure. Hang wind chimes from the top of the frame on every ground level window. Long and noisy ones. A burglar trying get in a window isn't going to risk the noise. Keep the outside of your place well lit at night. You can solar walk way lights at the dollar store sometimes. Go outside at night, if there is any area near the house that looks dark, light it up. On your doors replace the screws in the metal plates for your door knob with 4 inch long screws to make it more difficult for someone trying to gain entry by breaking the door jam.