Most folks know to make a checklist before they travel. Then, as they fill up their suitcase, they can just tick off the items they pack.
I take it a couple of steps further. I make separate lists for my checked baggage and my carry on backpack. Call me anal, but this really helps me bring everything that I intended to bring.
Being a frequent traveler, I just make up my list using a spreadsheet, print it out, make small modifications from trip to trip, and save it to my computer.
I also make a few lists that I bring with me to Thailand and use while I am there.
The first list I use is my upon arrival shopping list. This list includes items that I will immediately purchase when I arrive in Bangkok. It contains things like bottled water, phone card to recharge my SIM, and any toiletries that I will need. It used to include a cigarette lighter, but security has lightened up and I can now carry one on my person.
The next list that I use is my initial shopping trip list. I use this list when I arrive at my destination city. Bangkok is just a one-night stop over. This has my beverages, snacks, additional toiletries, and any other...