Many of these type of break-ins are opportunist and due to complacency on our part.
Get some bolts put on the sliding doors and/or some wood (2x1 or old broom handle) to stop them being forced.
Have some outside light(s) on.
Do your bit for charity and get a dog from canine friends.
Lock downstairs doors (kitchen etc) at night to restrict further access.
Get additional locks/bolts on the kitchen door etc.
Sounds a lot but you don't need a fortress, just make it too much trouble for the thief to get in, they'll go!
We all know there's no such thing as 100% security but I sleep ok at night (when I'm home!).