When I was a kid we were raised to not talk too publicly about when you were going to be away from home, for this exact reason. You'd ask a trusted neighbour to collect your mail so your mailbox wasn't suspiciously full. You could even buy power point timers that would let you schedule lights / TV / whatever to turn on and off at preset times, plus some random jitter to make it not obviously scheduled, so it looked like you were home.

It seems bizarre that in the face of all our perceptions of how cynical we've become, we've forgotten so much basic common-sense security.

(Of course you can still buy the timers and they still even have the jitter feature, but they're marketed as power-saving devices, not as security devices.)