There are many ways to make your home less enticing to intruders. Avoid planting large bushes that can conceal activity close to your windows and doors, switch your door locks to deadbolts which are much harder to break into and install motion-activated security lights to stop night-time prowlers.
Burglars are generally opportunists so the simple things like taking your mail and bins in, having a car in the drive, etc (including (especially) when on holiday) are actually really important things to do.
Security alarm systems have proven to be an effective deterrent, in fact I remember reading that somewhere in the vicinity of 70-80% of burglary claims (for insurance) come from houses without an alarm system and those with monitored alarms accounted for less than 5%. My system with sufficient sensors, cameras, control and monitoring from my mobile, and central control room monitoring all make my house safer.
Dogs can also definitely be a strong deterrent. - ProjectPete
I’ve seen an article point out a number of things robbers look for when picking targets. Things like rundown front doors with single locks, overflowing mailboxes, dark and overgrown areas and visible interiors. All pretty obvious things that would make a house enticing for a robber. I'm not sure investing in an alarm system is worth the expense and hassle. - MartyH