Last year I was able to visit around 10 new countries. It turned out that even to Japan I can just bring my hand luggage. It is possible to pack stuff for 2 weeks in a tourist backpack (35l).
If needed you can take a smaller bag for the camera. (Airlines usually state that you can have only 1 bag as hand luggage, but you actually can also take a smaller computer bag with you.)
1. Use vacuum bags
NB Always check them after purchase. Put in a sweater and a couple of T-shirts, roll it up, and leave it for the night. If the bag didn’t get air you can take it with you.
2. Cosmetics bag for cords.
The most convenient way for me is to have all my cords in one place under a zip lock. This also saves you time in the airport security check.
3. Always have one set of clean clothes in your hand luggage. (Advice for those who have check-in baggage.)
If you are flying to a far away destination and you are using several airlines, your luggage might be lost. This way you will have a spare set of clothes until you find your things.
4. Shirt / jacket with a pocket
I prefer keeping my passport close (not in my bag). So I always choose clothes that have pockets.
5. Don’t place your laptop too far away.
Up until recently it was very easy to charge my phone. I had a battery bank, which later was taken away in the Chinese airport. Now, I charge my phone from my laptop.
6. Download a couple of books on your phone.
Sometimes I cannot connect to the internet at the airport (or it’s just not there). In this case I read books. This is not very good for your eyesight, but a good way to kill time during a long transit.
7. Carabine for a water bottle.
I use this thing to hang my water bottle on my bag or backpack. This does look funny, but it helps save space. And my hand are free. (You can take a couple of regular ones as well.)
This one is a souvenir from Japan.