l wouldn’t count on that one - I’ve never had an ahso get through security. Have lost at least 3 between me and Jonathan.
Is that a USB toaster?
Frozen Flannery
it is always in my bag. While I do not travel as much as you, It has been with
me through Europe many times and almost monthly to Florida. no knife, prongs are not sharp.
A flashlight.
Advil or equivalent.
Imodium.
Band aids.
Other health related items.
A shoe polish cloth.
So many great suggestions. I’ll add my essentials:
Pepto Bismol is not available in many countries; my gastro doc recommends it above all other OTC meds for travelers tummy. It works!
Azithromycin Z-Pack antibiotics
Extra unlocked cell phone. Many destinations sell local cheap voice/data sim cards. Access to local cellular LTE/4G data is essential to me.
small bottle of dishwashing liquid (works on clothes)
gel handwash
Gore-Tex walking shoes
I never travel without my cyanide capsule fake tooth; just in case I end up stuck on the tarmac in a Spirit Airlines jet.
A small microfleece towel.
Renee always brings incense amongst many other things. The incense always makes us feel right at home and if you happen to be in a stale hotel room/ airbnb it really helps.
And me Zaltos and a portable turntable.
I enjoyed reading these suggestions - some of which I follow; others I just scratch my head and wonder why.
I often carry in my luggage a small cotton towel (wash cloth size) for spills, drying hands (lots of places do not have hand dryers or towels), or even cleaning a bench, seat, etc. Similar to the bandanna - although I would not use it as a bib. As evidenced by my shirts with small oil stain droplets from splashed slurping soup, I will not wear a bib.
Small packets of tissues - similar purpose - carried on my person.
Snacks - dried fruit, wasabi peas, nuts, salami, etc. Something to eat when you get to your hotel room and everything is closed.
Also, for an extended stay, I have taken a small portable speaker (UE Boom) for music; I much enjoyed having that.
A billiard ball, and a sturdy sock with which to swing it.
I thought I was the only one.
Two plastic hangers. I can wash and dry clothes during the trip. Saves packing weight and laundry costs.
Rolaids
Noise canceling earphones
Wine diapers for bringing back a few bottles in checked bags - bought a bunch on Berserker Day 8 or 9
I’ve travelled a dozen times a year for the last 10 years, mostly domestically, and lost exactly one in carry-on. That coming home from Anguilla. This is the cheap plastic variety without a blade. Cost a buck or so.
I’ll add:
Tide Pen & Travel-sized bottle of Woolite for any emergency/stain. If it’s the whole family, I pack Tide Pods and Bounce Sheets in an empty Talenti Gelato jar so they don’t get squished. Nothing is worse than having to buy a whole bottle of detergent on vacation.
Travel-sized Wet Wipe packs in every bag so you don’t have to search for them.
Bottle opener keychain. I always end up buying interesting sodas/beers I can’t twist open. I bought these https://www.amazon.com/gp/product/B07785LK87/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1 because they were attractive and they also tighten screws 
They took one from me, as well. now the AhSo goes only into checked baggage.
Along with fresh coffee beans, a small digital scale, some paper filters and a Kalita Wave 185 brewer, this:
https://www.amazon.com/Porlex-Mini-Stainless-Coffee-Grinder/dp/B0044ZA066
I know it’s the opposite of packing light, but I find it’s a wonderful thing to be able to make a perfect cup of coffee when travelling.
I’ve given up on carrying any sort of wine bottle opener as I’ve found that even the “TSA compliant” versions end up causing the bag to be pulled for secondary screening. While the opener ultimately gets through, it can sometimes be a lengthy wait for an agent (usually when your flight is just about to depart). I just drink beer on the road now.