If you are paranoid about having clean teeth, take a small tube of toothpaste. If you can do without, buy fresh stuff when you get there, and then if you don't need it to come home, leave it behind. Same with shampoo. We all have our favourites, but if you can get by with what's provided on your stopover(s), then get shampoo after you arrive as well.
Medication is important if you have to carry it, but thankfully this time I am a Senior, and have been getting my prescriptions at the cheaper rate since I turned 65. When we went last time in 2007, I had to fork out over $500 for tablets and eye drops before we went. You also have to arrange to get enough to last you for the entire time away. I always take photocopies of prescriptions with me, in case all is lost, and I may be able at least to indicate what I need to an overseas pharmacist. It also proves to whoever might ask, that these are your prescribed drugs, and you need them.
Batteries and chargers are another thing. We want to take our laptop, both for internet access and for keeping a record of our trip. Plus, two cameras, a digital sound device, (to record family conversations and information), mobile phones, etc. etc. And they all have to be charged!!!!
It's about time all the companies got together, and produced a 'universal charger' that would do all phones, all cameras, laptops, devices or whatever.
Thankfully, with cameras, you now don't need to carry rolls of film. You just have to make sure you have enough storage on your memory cards, and then don't lose them.next time - cash and cards, and coffee...