I am taking a few minutes to write down my "philosophy" on making a home physically secure.
Background
Every layer acts like a filter; some unwanted threats will slip through while some desired contacts will be repulsed.
This is similar to a quality-inspection system in a factory. Important characteristics are inspected at several stages because...because some defective material will slip through even the best inspection stage.
Taking a page from quality-inspection, having multiple "layers" is a good plan and so is having effective layers.
The calculation for the amount of defects that slips through is 100% - (100% minus catch-rate)^(number of inspection layers). So four "layers" that are 80% effective has a calculated effectiveness of 1.0 - (1.0-0.8)^4 or an effectiveness of 99.8%. In a similar way, four sequential filters with 60% effectiveness have a combined effectiveness of 97.4% or almost 13 times more "leakers".
At this point, some of you who have been paying attention are likely to point out, "Hey, that is fundamentally wrong. The first filter removes the lazy and stupid. Later filters will never be as effective."
I have no argument with that observation. Which leads to the next observation: The filters must be complimentary. That is, they filter on different attributes.
Concrete examples (not a complete list)
Filter 1.0: Don't be the house that "stands out". Don't be a $500k house in a neighborhood of $200k properties. Don't have vehicles that are twice as expensive as the typical neighbor. Don't be the first house in the neighborhood to have the snow melt off of you garage roof. Don't flaunt expensive toys. Keep your garage door down and don't put political signs in your yard.
Filter 1.1: Drugs, Cash and Handguns are the lightning rods that attract the wrong kind of attention. Felons cannot legally own firearms and yet guns are keystone to the image many felons desire. Unlike a flat-screen TV, a "hot" handgun can be fenced at 100% MSRP. This is where you must be an attentive parent. Sometimes a kid will post pictures or write things on social media that makes your home a target.
Filter 1.1.1: Breakdown all boxes before putting them out for the trash-man. Remove or obscure logos or take broken down cardboard to recycling.
Filter 2.0: Set the stage. Great doors. Great locks. Good windows. Keep "inside" inside and
"outside" outside. Sorry if you love sliding, glass doors...but they
don't cut the mustard.
Filter 2.1: A barking dog calls attention to the person with ill intentions. Those kinds of people hate attention.
Filter 2.2: Don't allow your landscaping to shelter vermin. Vermin hate light. They
hate visibility and attention. Motion activated lights are a good move.
Removing tall shrubs that assailants and people plotting to break into
your house is a good move.
Filter 3.0: According to Fer-FAL, the easiest way for a motivated goblin to breach your home defenses is to wait until you come home after a long day at work and then bum-rush you through the door you just unlocked. You are tired. You are hungry. You are hyper-focusing. Be mentally prepared to drive around your block if anything looks "goofy". Two hinky-looking dudes loafing near your house? Maybe call the spousal unit and kids and call an audible that you are going to meet at Vito's for an early dinner.
Cheap-and-easy
Cheap-and-easy, that's how I roll.
Most of these steps are passive or don't require much effort.
I don't consider myself an expert on gadgets and bang-sticks for home security but will take a stab at a blog-post if there is interest on the subject.