Ninja Packing is a fine art that you can master with time and experience. As a former long-term traveller, I learned the hard way that the less the better, even if travelling for shorter trips. Travelling with a carry on can be more than sufficient for most destinations and will allow you freedom of movement while sparing you a lot of stress.
The priciple of ninja packing is that the less you carry the less you’ll stress. Carrying around plenty of clothes means struggling with the weight when travelling and stressing out when trying to figure out the right outfit. On the other hand, carrying less allows you to have a few stress-free, preplanned outfits that you just have to wash more frequently. Laundry is usually cheap and easy worldwide and, trust me, an extra laundry is better than carrying around plenty of smelly clothes just because you have enough.
Ninja packing is not an exact science though. Wheater conditions, planned activities, sports and the lenght of the trip can make a huge difference. Thus said, over the years I fine-tuned my basic South East Asia packing list (or for warm Countries in general) and I’m pretty happy with my less than 6kg carry on 50L backpack.
How to choose the right backpack
I travel with a Decathlon 50L backpack with front zipper and rain cover (bought separately). The front zipper is key, because it allows you see the full content of your backpack if you pack it properly. I find the 50L size super flexible. In its full capacity it can be used as a hold luggage for long trips or for journeys that need both light and warm clothes. When used for warmer climates though, it can be filled partially (all external pockets must be empty) and actually fits as a carry on.
I also carry a daypack that can be folded and put away when on planes. This one varies depending on the trip. If I have to hike a lot, I will take a proper outdoor backpack and if I have to carry my laptop I will have a properly padded one. In this case I’m stayng two weeks in Portugal and I wanted something sturdy enough to go hiking and at the beach, but also nice enough to be weared with dress and sandals at night.