We don't have a 'secure' checklist per se, it is just a list at the end of the normal procedures section in our manual. We do it only for a terminating flight, when we know that the airplane will overnight etc.
ADIRS, as you mentioned, are turned off every time we do the 'Parking' checlist, after every flight. The 'secure items' are: 1. Oxygen crew supply
2.CRT's
3.Cockpit lights
4.No smoking sign
5.Battery switches
all to OFF
and turn off APU and APU bleed if they were on.