Agreed, checklists can become a cargo cult. Also, checklists don't always need to be written down; just systematizing some mental checks can be helpful enough (e.g. "phone-keys-wallet").
I like to organise things in groups (for example, for paragliding I had 3 x 3 items, one for environment, equipment on the body, equipment "off" the body, respectively), or use mnemonics (before leaving plane: MaSeLToF (Main switch off, Sun guards set (and sun glasses removed from cockpit...), Logbook completed and hours noted, Tie down and chocks installed, Flight plan closed).
