[smcl]

Having been locked out at annoying, inconvenient times of day I started follow the same process a few years back. I feel like I'm going mad when I'm doing it though, stepping out of my flat stopping, staring at my keys and consciously placing them into my pocket. I'm so glad someone else does the same.

[oska]

I always lock my front door from the outside when I leave the house. This requires using my keys (unlike locking it from the inside). This means I never leave my keys behind. It does require remembering to lock the front door but I don't have any problem remembering to do that.

[Tor3]

My front door can only be locked with a key.. that effectively prevents me from forgetting my keys inside.

[gmueckl]

I have sinilar ritual when leavong my flat: I pat down all my pockets to check that everything I need is there: keys, paper tissues, phone, wallet... I even used to do it with a foot deliberately positioned in the doorframe to prevent myself from closing the door with the key inside.

[endgame]

I count to six: wallet, watch, keys, phone, work pass, pen.