I like a colored zip tie snipped off at the end so no long cord is visible - but if someone is trying to get in they have to make it obvious.

Its enough security so -

1. you know when tampering occurs and

2. It deters an opportunistic thief.

3. Its "low profile" is not enough in and of itself incentive to break in in the first place.

Its also harder to replace than a standard black zip tie and the TSA is unlikely to have the exact color sitting there.

Uncle Dave