I maintain a travel list created on my computer. When its packing time I print it on paper, it's much easier to move around the house and collect what I need while holding a paper in your hand.
Each item which goes into my language is getting checked off. Sometimes their are items which are not on the list but need to be their. I add it to the list and use a highlighter to make it clear an action need to be taken here - Update the computer list.
If I find something which need to be updated, like the same item twice, I highlight the item with a marker an write "delete" on the same line.
When I finish packing, it's goes into the "harvester" (I will explain what it is in future posts). Coming back from my trip, it's waiting for me to be processed when I have time.