Note: Credit where it is due, I got most of the home layering ideas from Mas Ayoob.
Mine just stacked up over the years. My burglar bars came on the house when I bought it although I did add front and rear door bars. Alarm system was my first move and saved me from a potential hugh loss in valuables. Our local deputies suggested the lighting to a neighbor while we all talked about an event that happened next door. Cameras were installed after someone stole a metal welcome mat from out front of my house while my boys were home alone and in serious fear (strange man looking shady out front stealing things). The wife and I wanted to be able to watch the house from our cell phones.....we love this BTW.....my boys not so much LOL. Finally the dog. My boys get credit for this because they whined and cried until I gave in. The Rotty is turning into an early warning system and a buttocks chewing machine.
I guess I just lucked into my system over time.