I have to have EVERYTHING I'm bringing on a list. If I don't have it written down, it doesn't wind up coming. Before I started keeping very detailed lists, I'd do things like show up with no socks, or toothpaste but no toothbrush... All sorts of ridiculous errors.
I now keep my packing lists in an excel file, divided into columns for me, each of the kids, and communal (my husband manages his own packing). Each page in the spreadsheet is a different trip. So, if we're packing for a trip to a b&b in the north or to the States in the summertime, I can refer back to last year's list as a starting point and then revise from there. And with a laptop, I just carry the computer from room to room rather than printing a list and crossing things off with a pen. Much easier to revise that way.
As I pack, I format that item as
strikethrough text. Once most of the items are packed (or more realistically piled in a heap on the dining room table waiting for someone to stuff them into a suitcase) I then highlight the remaining items in yellow so that I won't miss them out among the rest of the chaos.
Surprisingly, this is one of the only areas in my life where I'm this
anal organized. It was born out of necessity -- and a dissatisfaction with arriving in out of the way places in the middle of the night to discover I don't have a toothbrush or my kid doesn't have socks!
Packing lists - they work for me. Check out Shannon's Rocks in My Dryer for more WFMW tips.