stay off facebook etc but if you must use these things don't mention the holiday until you have been.

I always use the keep safe service for post

Around here we don't make it a secret, we tell each other and keep a careful eye on each others property. The official advice many yers ago was "be a nosy neighbour" and it does work.

Nowadays we just make sure that all the doors and windows are locked,and the burglar alarm is set. Used to leave a key with a neighbour ,but since they have moved away we don't bother now. In fact, we don't normally tell them we are going away.
We try to persuade one of my daughters to visit if we are away for more than a week ,just to pick up the junk mail (which is virtually all we get nowadays !)
My s-i-l is a copper and his view is that if a "professional" wants to break in, he will, whatever precautions you may take but using all the locks will deter all the chancers.