Sometimes I'll jot down a more detailed inventory of what I need for the next trip, but most of the time I just run checklists in my head. "OK, so I go to sleep - what do I need? Toothbrush, toothpaste, sleeping bag, ground sheet, tent, clothing appropriate for the season". "OK, let's eat breakfast - what do we need? Cocking gear, fuel, oatmeal, spoon, bowl, COFFEE, ..."

Far from foolprof - but I've yet to forget something really important. Some minor stuff has been left behind, mostly additional nice-to-have comfort or play items that we intended to enjoy on that particular trip.

I've played with the idea of keeping more detailed inventory of everything on every trip but nah, it's too much hassle. I'll start on writing a checklist just to get the juices flowing and then do the rest in my head.

I reserve checklists for really important stuff that can't be done before the last minute. Such as "move frozen food from the freezer to the cooler" or "pack phone charger in the morning".