And when away, leave one light on inside somewhere, and a t.v or stereo blasting. at least try to make it look as much like someone's home,as possible.
Better still-another poor-man's deception trick.
Download and install Audacity (free recording software) and record a few minutes worth of a party,crowd or gathering of some kind-or the sound of from a t.v. show/movie, etc.-save the file-then open it in Audacity, and create a loop-where it repeats over and over.
Just genral crowd noise -people chatting etc-then when u leave- play back the audio file-reasonably loud- in an on-going loop. at least gives the impression folks are there...