A few key things
-security checks at the gate itself (Changi airport in Singapore for example)
-pass through security at every airport,even when connecting
-hire real security personnel instead of the half wits who can't spell their name on their name tags correctly.
-I think luxuries such as curbside check-in, telephone check-in, etc. will be a thing of the past from now on.
-I think the US gov't should issue federal ids-passports should be required for all passenger regardless of whether domestic or international travel. No more licenses issued in 1972 in Vermont should be accepted
Things will be very different from now on when we fly but it will be worth it to prevent anything remotely similar to yesterday's incident.