My first choice for a home security system is always a loud dog. It's a proven fact that criminals will avoid a home that has a dog that raises hell when someone shows up. A barking dog draws attention and the criminals are unsure if the animal will attack.
Now for extended leaves a pet isn't the best option for obvious reasons.
I've pulled security details for everything from marines to foreign diplomats ranging from forward operation bases to swanky condos and there is ALWAYS several layers of security.
In my personal home I have a fully fenced yard with an intercom/lock on the gate , this is the first level
Once you are in the perimeter of the yard within 50 feet of the house motion lights turn on (all are linked together) , this is the second level.
The front and rear doors have a very discreet camera so we know who has come to either door. Both of these doors have reinforced frames and the doors themselves are reinforced with high quality door handle and dead bolts. This is the third level.
Inside the house all windows and doors are linked to the home security system that also interfaces with the home smoke alarms. I use ADT , the system alerts our phones as well as local law enforcement and fire if need. The alarm is also hooked to a 160 decibel siren so the neighbors are going to get nosey. Drawing attention is a great thing here. We also have several dogs , nothing special just two rescue mutts and a teacup Yorkie , none are mean but they all raise hell when they hear something out of the norm. This is the 4th level
Lastly , all important valuables are locked in a safe so if someone gets into the house and hasn't tripped over the dogs and died from them try to lick them to death. Then anything of real significance is locked in safes that can't be removed without serious work and machines. Law Enforcement will be on scene within 10 min and if they are not caught we have a great picture of what they look like.
Of course things are different when we are home , we are a very active shooing family and everyone who needs to know , knows where a gun is and a home invasion by anyone short of reasonably well trained law enforcement is going to end very badly for them
Invest is the best systems you can afford , even it's it's just a $50 mutt from the shelter.