Not really much, tbh.

Decent quality door locks
Clear line of sight from the street to likely entry points
Loud alarms so if they do break in they're not likely to stay long

If someone wants to get into a house, there isn't much you can do to stop them unless you're rich and can afford exotic shit like bullet proof glass windows and thick metal reinforced doors.
All to can really do is discourage crimes of opportunity by making them seem like bad opportunities.