me_irl

If you have difficulty remembering if you did a daily task, like locking the door, you are supposed to do something novel when you lock it, to be sure. So maybe today you spin around in a circle when you lock it, maybe tomorrow you tap your forehead four times, the next day you whistle a tune, and so on.

You can repeat novel cues over time, the trick is just doing a different thing every day so the action itself stands out as a reminder that you did the important task.