For context I have traveled as much as 80%, international. I have mellowed and am down to about 8 internationals and 25 domestics per year. I’m tracking >150k air miles and maybe 80 hotel nights. I’m a sales guy so I have to look reasonably put together, and most of my trips are single day in a given locale and contained by my choice within a week; last week was typical — Utrecht, Helsinki, Billingstad, Bergen, Stord, and ålesund. This week is mellow, just two days in Seattle.
I never check bags. If a trip is mostly one city like a trade show then I’ll probably do a (euro sized, Rimowa hard side with latches not a zipper) roller paired with a 20 year old Tumi briefcase; most of the time I get by on a Goruck GR1 26l, except in winter. Having a single bag makes the flight-every-night trips a lot easier and prevents me from having to roll a suitcase into a customer, or down two miles of European cobblestone streets.
Most of my trips are done with a sport coat, a pair of trousers, jeans, two dress shirts, and maybe a sweatshirt. The separates help because I do a lot of time in Norway and sport coat plus jeans is as dressed up as you can go there. If I’m at a show, seeing government, etc the separates are replaced with a suit, and I’ll add a couple of ties. If it’s the height of summer I might pack an extra dress shirt. In summer, I almost always wear short sleeved dress shirts, which in addition to being cooler pack much lighter. In the dead of winter I will replace the sport coat with a packable puffy jacket, if the environment is suitable — it works ok in Norway and the Netherlands, not so much in Finland and Germany. Usually I get by with a pair of gloves and a scarf.
Summer suits and sport coat are Brooks Brothers Brookscool. Winter suits are heavier wool flannel. Shirts are brooks brothers slim fit non iron, and have been for >20 years. Shoes are Ecco. Shoes should be loose at home — feet swell a lot with flying and walking. Undershirts are Duluth— three for a week in the winter, five in the summer unless I think I’ll be able to launder. Socks are cotton, three spare pairs for a week, they can be washed in the sink if necessary but can usually be reworn. I will usually wear a casual t shirt on the flight over and sleep in it every night. Toiletries are constrained to a 0.5l countcomm bag and liquid is separated in a ziplock because Europe doesn’t have precheck. Amazon sells folding hairbrushes, travel sized toothpaste and stuff in bulk. I use an aggressive antiperspirant. I carry a disposable razor.
Amazon also sells packing cubes. These are essential. Not only do they keep stuff organized, they allow you to pull your clothes out of the backpack and leave them in the rental car while you go in for the meeting.
https://smile.amazon.com/dp/B014VBGU..._IWiODbQ7DKB3X
I carry all my charging connectors except the laptop in one little countycomm bag. I do carry a spare battery, and enough phone cables to forget one in the rental car.
I like noise canceling over the ear headphones but they’re too big most of the time. A Bluetooth earpiece and some cheap earbuds for Skype are all that usually make it in the bag.
Eyeshades, earplugs, disposable toothbrushes as Joe mentioned (
https://smile.amazon.com/dp/B071DPCB..._f1iODbVM1HJG2), lens wipes, a rosary, two pens, my diary, a thinkpad x1 carbon, a kindle paper white, Tylenol, boiron ColdCalm, antacids, travel tissues, chewing gum, a vapur (
https://smile.amazon.com/dp/B007UU6J..._t5iODbQ00F7KX, these are badly made and disposable, I go through one a month), spare glasses unless I’m wearing them, sunglasses.
Working out is a nice idea and I pull it off sometimes but that adds a bunch of stink. Bring plastic bags to separate thing. I like Merrell vapor trails, as a packable running shoe, and two-in-one shorts, and a quick-drying singlet.
I don’t bring food. If I’m hungry I eat, if there’s nothing to eat I fast. I drink a lot of water and a lot of coffee.
Booking international flights is a whole thesis in and of itself. For my application the essence is flexibility.