Not counting the clothes on your person (jeans, shoes, shirt, sweater, maybe a jacket if you are going to frigid places), your smartphone and wallet (with debit card) in your pocket , probably less than 10 things:
- Laptop + Charger (I recommend Macbook Air 13", the best nomad machine)
- Minimal clothes: 5 sets of underwear, 2 shirts, 2 shorts, a pair of sandals
- Copies of passport, debit card, issued visas, etc: documents in case of emergency
- Headphones/earphones that suit your taste
6 (personal preference) A small thermos (<500ml)
7 (situational) mouse/drawing tablet depending on your work needs
8 (situational) Backup battery (that can be used for both laptop or smartphone)
9 (situational) Hard drive for recoverable backup of your laptop
Anything else you take along is a non-necessity unless relevant for your work, and more likely a liability than an aid. Keep in mind that as a nomad, the monetary cost of having to buy some $0-$100 item that you situationally need is negligible compared to clutter, weight, volume and stress given how much time your belongings will spend weighing your shoulders down rather than being put in use. I’m not a coffee person, so I skipped the thermos, but this is essentially what I went on my last nomad leg (6 months long, 5 countries/cities) with. I didn’t miss much at all. I didn’t have a jacket and it turned out I needed one in Japan in April, so I had to buy one from Uniqlo (got an ultra-compact down jacket that’s the size of a soda can when rolled up), and I had to replace my headphones which got busted, but that was about it.
I use a Tortuga Travel backpack, so I had plenty of space to spare after this much stuff, in which I carried one of my side projects, a board game I’ve been working on, and which serves as a great icebreaker with people I meet. I carried one sweater and one dress shirt more than I recommended above, and I wish I hadn’t.