People like to signal that their doing something to improve safety, life, comfort, whatever. Signal safety of kids/planes/society/etc.
Now that requires active Security measures on planes and airports. While a lot of passive security measures can protect people just as well.
1) In nuclear power plants there exist bomb sniffing hardware that doesn't analyze the contents of objects one by one but the air itself, a lot of bombs have volatile Chemicals that enter the air, by analyzing them certain chemicals can be determined to be present. Put them in the air system of planes, In the vents at airports, at key checkpoints of airports. If something is detected perform enhanced security measures on everyone.
2) Plane Design - Pilots stay in cockpit, train them for contingencies (people complain about some things but get over it as they can do it on their own time anyways). Look for other passive safety measures in airplanes.
3) Attempted density analysis of luggage and packages. (They have to weigh the things anyways for determination of weight requirements and size). Using sensors and software an approximate volume can be determined as well as an exact weight. If Density is outside a likely volume for clothing for example, flag it for enhanced analysis.
4) Metal Detectors - Already present and they detect metal on the body. Which classifies most guns and knifes
5) Certain special conditions, A wheelchair for example if the most likely case can have the person transfered to an airport wheelchair while their wheelchair is analyzed for discrepencies and if found enhanced search of it. If medical requirements require things like Oxygen, or non-movement, use certain enhanced methods.
6) Heat sensors to detect things like lite matches.
That would catch a vast majority of problems while at the same time preserving more privacy and reducing the load on workers who can have certain ideas about wielding authority or using their power.
Active Defenses -
1) Provide classes to passengers on how to subdue hijackers, (even if they have guns that wouldn't be a normal situation such as a mugger), it provides signaling and an sense that there are even more people to protect commercial flights.
2) A police presence as well as all employees trained in certain things during emergencies.
3) Accurate suspicious person list that doesn't say no fly but instead enhanced searching.
1) Lots of signs with reputations saying it's protected.2) Allow people who went through a safety course to wear a badge, (doubly good, they get to signal their helping and others get a sense of improved security)
3) Published material on safety and current non-classified events of interest, as well as studies showing what impact it has had.