Look at my bag (the one on the left) as I enter China sometimes in late 1990s. I used to get carried away and pack everything that I might need. Over the years, as I discover new fabrics, technology etc, and as I learn to live with less and less stuff, I have been trimming what to carry. This is my current arrangement.
Most important is the bag. The brand doesn't matter as long as it is somewhat waterproof and sturdy.
The stuff inside, I use mesh case for packing sundry stuff, as some airport security wants to visually inspect stuff and mesh is a good material to pack razors, tooth brush and moist swimwear, helping them dry faster.
- one case for the charger and cables, keys, currencies and cards for other destinations
- one case for toiletries (some airport security like to able to visually inspect stuff)
- one case for swimwear
- the larger case packs one or two change of clothes
- a notebook - doubles as storage for tickets, maps etc
- iPad for writing and presentations