Along the same lines, I carry a little camping spork like this one in my travel bag. Because sometimes I bring back leftovers from dinner or buy a little something to eat. And hotel rooms often don’t provide any utensils.
When I travel with my wife, she usually brings single-serve packets of oatmeal for her breakfast, which she makes with hot water from the coffee maker (or microwave if there is one). And borrows my spork.
Adding my vote for TSA pre-check. $85 lasts for five years and you skip a whole lot of misery at airports.
If he wants to reduce the likelihood that he’ll catch a bug on the plane, which would suck if he’s business traveling, some sanitizing surface wipes are good to bring. Once you’re seated, wipe down all the surfaces that you touch: the tray and its little lock, the armrests, the window slide, the seat belt lock.
My secretary signed me up (but she knows all my vital statistics).
Also, Clear. Just signed up last week and I’m already a big fan. It works at many airports and sports events.
If any of the travel is international, Global Entry speeds you through US customs and confers TSA Precheck, for $15 more than applying for just Precheck.
I haven’t tried Clear, primarily because PreCheck averages ~5-10 minutes, depending on how busy it is and I’m not sure the marginal improvement is worth the price.
Nexus is $35 less than TSA-pre and includes it as well as global entry benefits. I’m not entirely sure I understand the pricing. I assume that have another reason to want people to sign up that way.
Nexus is a great deal, but you have to get it in Canada, or at a couple of inconvenient places on the border. I was going to get Nexus, but it took so long for my background check to clear that both my Canadian trips had already happened, so I ponied up for Global Entry, which I could get at my local airport.
That’s true. We had to travel to Blaine from Seattle for interviews for the whole family. Ended up turning it into a long weekend vacation to Victoria, so it wasn’t that bad.
Getting back to the OP, “a rather Spartan individual who does not shop for himself much” will be a challenge to shop for. I’m sort of like that myself, so I think the risk is high you’ll buy something for them that is never used. Some people just don’t need that much stuff.
Most of the advice for specific things in this thread seem sound but quite personal. Personally I travel for business quite a bit and largely don’t feel like I need anything out of the ordinary. I stuff my usual toiletries in a zip lock bag, pack my standard commuter earbuds (I have young kids myself, so other kids screaming on airplanes just sounds like the sweet sound of no responsibility to me 
), and don’t care about walking barefoot on hotel carpets. So a travel specific headset or kit I only pull out for airplane travel would be more trouble than its worth for me. I like taking minimal stuff. In fact if its just a quick couple of days hop down to SF I can just stuff some clean underclothes and shirt and toiletries in my usual work backpack and call it packed.
That’s not to say that some of the stuff mentioned in this thread wouldn’t be appreciated. I just don’t think you’ll know what that is until the specific individual has done a few trips and identified a specific pain point that specifically infuriates them …
I signed up for Global Entry a few months ago even though I have no immediate plans to fly overseas, because it’s only fifteen bucks more than Precheck (and that’s a total of a hundred bucks for five years). I wasn’t familiar with Clear, so I just Googled that and it’s so not worth it for the few times I fly and that it’s $179 per year.
Good quality carry-on luggage and laptop backpack (recommend Briggs & Riley) You do not want to check bags especially when traveling for work, a lost bag is HELL
TSA Precheck, via Global Entry or stand-alone
Silicone travel bottles less than 4 oz. each to meet TSA liquids requirements
Charging block with multiple USB outlets for cords
Good quality wireless earbuds
Things I always travel with…
A small wireless/bluetooth speaker for chatting to my spotify account in the hotel room.
A subscription to Audible for when I want to read a book but am also driving (or sitting on a plane with my eyes closed).
A corkscrew (sans knife attachment so it passes security in my hand luggage).
I have different kits for different trips, I don’t bring all but pick and chose what I would like. Some of them include, or have included:
Fire TV stick, HDMI cord, iPhone to HDMi adapter, extension cord(s), USB outlet adapters.
Cooler
Travel dish set, one of those backpacks for picnics. Plates, cups, utensils, and some added/replaced items including cleaning supplies for them.
A plug in pot. Nothing fancy, under $20 at Walmart, can cook anything with it, and cook it well.
(with the above 3 items I have a total kitchen)
Kureg coffee machine - I upgraded my home one and now have the option for a travel one, - it’s the smallest one they make.
Immersion heater
Pipe wrench and shower head. This used to be mandatory back in the 1990’s with hotels on the low flow shower head bandwagon, but show water pressure/flow has improved and i no longer bring this.
Floppy pillow
Regarding luggage, my carry-on bag is a soft-sided four-wheeled Samsonite suitcase, with telescoping handle. The OP’s friend who is just starting to travel regularly should think about whether he/she would prefer four-wheeled luggage, two-wheeled luggage (normally this sort has to be pulled at an angle) or unwheeled luggage, such as duffel bags. Some carry-on luggage comes with backpack straps. And some luggage is hard-sided (sometimes with a zipper between the two sides of the clamshell) and others are soft-sided. All of this is a matter of personal preference and your preferences may change as you travel more. I recommend a trip to a department store luggage department (Macy’s, I think still has staffed luggage departments) or even a dedicated travel and luggage store, if you can find one. It may be cheaper to buy luggage on-line but I think for someone starting out, the personal attention of a good salesperson may be helpful.
Edited to add, because tastes change, I don’t really recommend buying the expensive sort of luggage right away. The cheap stuff lasts long enough. The fancy stuff does come with terrific warranties, but that may not help if you need to send in the stuff for repair, or your tastes change.
I think this is the best suggestion. For one thing, even if he already has one, two is even nicer–you can always leave one charging and carry the other. And they do get lost, so a back-up is nice.
Also, and maybe it’s just me, but backup cables. They just go bad after a while, and it’s nice to have a set. Do you know what type of phone he has?
How much do you want to spend?
Last summer, flying back from Atlanta, I was seated in the nursery apparently. No fewer than five children young enough to be held the entire trip were seated within three seats of me. One of which was distinctly unhappy. I could see them screaming, but I just watched my movie on my kindle with these:
https://www.amazon.com/dp/B0753GRNQZ?aaxitk=J6dErO44MJsF465mlTSY.w&pd_rd_i=B0753GRNQZ&pf_rd_p=3fade48a-e699-4c96-bf08-bb772ac0e242&hsa_cr_id=3929136400301&sb-ci-n=productDescription&sb-ci-v=Mpow%20Flame%20Bluetooth%20Headphones%20Waterproof%20IPX7%2C%20Wireless%20Earbuds%20Sport%2C%20Richer%20Bass%20HiFi%20Stereo%20in-Ear%20Earphones%20w%2FMic%2C%20Case%2C%207-9%20Hrs%20Playback%2C%20Noise%20Cancelling%20Microphone%20(Comfy%20%26%20Fast%20Pairing)
My brother had to fly for business meetings where he had to take a dress shirt and tie. He has the same ironing skills at 50 that he had at 8.
+1. I’d been wanting a pair for quite a while, and used a recent plane trip as an excuse to get them. I also use them when I commute by Metro - can’t hear an audiobook or whatever otherwise. I got Bose QuietComfort; Sony has a similar pair at the same price point.
If he reads, and does not have an ereader, a Kindle or Nook is a good option. It’s an additional device to keep track of - but it does books so much better than a phone.
A small nightlight to keep in his toiletries kit. Makes late-night bathroom trips a lot easier: he can see to find his way in an unfamiliar bathroom, without blinding himself by turning on the overhead light.
Actually, I recommend everyone carry a small but powerful flashlight in their toiletries (it is amazing how bright a light you can get in something the size of your little finger). In an emergency, while in theory there is supposed to be emergency lighting, quite often you end up in pitch black situations. While a smartphone is a reasonable make-do, nothing beats an actual flashlight.
I haven’t carried a flashlight for anything less than a quarter-mile in the dark woods since I realized my Treo produced enough light to walk by. And most phones have a “flashlight” function now, that even works for that hike in the dark, over rocks and roots. (ask me how I know.) A quarter mile will drain the battery some, but for walking around a hotel room, it’s surely not worth carrying a flashlight!
One thing I gave my kids which I haven’t seen mentioned is a portable electric toothbrush. Under $10 at CVS. They were lugging their electric toothbrushes and charger around with them on long trips, and really liked not having to do that.
I always take slippers. The only problem with TSA precheck is that I’d hope his company would pay for it as a business expense.
Also a Kindle, since I can load lots of books for a trip, and load more if I run out. Bujt I get very nervous at the prospect of not having anything to read.