I do what I call "the Moron Macarena" just before I close the door. I pat each pocket and cross my arms patting the pockets again just to look extra stupid when I do it lol
Same except keys are clipped on a belt loop and I have a handkerchief with my wallet in my right front pocket (Japan is super humid so a lot of sweat-wiping happens). Also right-handed, but I hold my phone with my left and enter the passcode with my right hand (I don't use the fingerprint scanner)
I'm pretty much opposite. I don't even know why I carry this unknown mass around in my pockets. My keys are probably in there, otherwise the car wouldn't start.
I have ADHD and recently just quit nicotine. So for the past few months I run through my mental checklist including the vapes that are no longer part of my checklist because they were part of it for so long. then I have to consciously tell myself I don't vape anymore and have to redo the list In my head without the vapes. I never feel like I have everything...
This is me minus me checking specific things in the house, like door closed, AC off... Check for keys, wallet, and phone. Shit. Need to check the house again. Oh. Do I still have my keys, wallet, and phone?
Sometimes I think of something else that might have needed checking so I do the whole thing over again.
Lock the door. Check it's locked. Press elevator button. Go back to see if the door is locked (I'm right next to the elevator so it's not that crazy). Sometimes go downstairs only to go back upstairs to make sure the door is locked.
This is why I started wearing hats everywhere. I have to find my hat which triggers the "Have I got everything?" thought process. If I go outside without my hat it definitely triggers the "Double check EVERYTHING because you clearly arent switched on"
When I was the last one leaving the flat for a while, I put a post-it on the door, not only specifying what I needed to pack (I’ve had that down for years), but also for things to check (open window, balcony). I always checked those things, anyway, but checking (and affirming) that I checked gave me peace of mind.