"Finished" is the international word for "I'm done" "we're out of it" "not running anymore today" "not running anymore ever" "closed", you get the idea.
Always check your flight status early because you might not always get notified if any changes or cancellation.
Always keep tiny luggage locks on your backpack and a hand on your purse. Thieves really will try to do the grab n' run with your purse or get into your pack, especially in crowded areas.
Another "this might just be me" but when I'm not using my pack (like in a hotel room or at night), I close it all up. I don't want any roaches or spiders climbing in for a ride!
Bring a large pashmina or a sarong with you when you travel. It can be a blanket, a towel, a shoulder cover for modesty, a dress, you name it!
Bring an empty water bottle to the airport so you can fill it in a water fountain once you are through security.
Delete your browser cookies and/or use incognito browsing when searching for flights. The prices shown will actually go up the more you search for the same flight!
Don't wait till the last minute to get money from the ATM because you might not find one that isn't broken or out of money.
For your Global Entry interview, you can get it done more quickly if you are either traveling soon through an airport that offers interview on arrival, or just keep checking for cancellations on the website every 20 minutes or so. You can probably get a same-day or next-day appointment.
Grab a business card from your hotel and keep it with you at all times. If you get lost or just need to tell a driver where to take you, you will have the address and it will be in the local language.
Hang on to as much "small money" as you can. Everyone wants it, nobody has it. Meaning nobody will EVER have change for you if you try to pay with too large a bill (and by large bill I mean not a large bill at all; one they should by all means have change for). Spend big bills every chance you get like at a grocery store or larger restaurant.
I find it best when asking directions, to ask a local woman. There seems to more a sense of camaraderie, especially in countries where men dominate, I feel it makes you much less a target and more of someone that they might help.
I have found I get the best exchange rate using ATMs even taking into account the ATM fee. Some banks will even reimburse 3rd party ATM fees!
If you are checking luggage, pack an outfit and a few main essentials (like a bathing suit) in your carry-on in case your baggage gets lost.
In countries where you should not drink the water, make sure you rinse with bottled water when brushing your teeth and don't rinse your mouth in the shower, either.
In many developing countries, you do not put toilet paper in the toilet. No matter how used the paper is, fold it in on itself or wrap it in more paper if you have to, but put it in the trash bin (which is unfortunately not always one with a lid on it).
In the US we say "to-go" for food we're carrying out whereas the rest of the world says "take-away". If you are going to use English, use "take-away". Otherwise learn the local term for it wherever you are. For example in Spanish, you say "para llevar" (for carry).
Keep copies of your passport at home, hidden in your main bag, as well as a photo on your cell phone in case your passport gets stolen.
Ladies, wear panty liners on long flights. You can change them during layovers or mid-flight to keep fresh.
Mosquitoes don't like wind. Keep a fan on to help keep them away.
Need some gas for your motorbike? Ask for "petrol". The word "gas" won't get you anywhere. Ooh look, I made a funny. ;)
Only carry with you whatever cash you need for the day. Keep your main cash and credit/ATM cards hidden in your locked main luggage or in your hotel safe. Also keep an emergency stash of your local cash hidden deep in your luggage.
Some credit cards automatically provide travel insurance. Research your cards before purchasing 3rd party insurance.
Spray your ankles with bug repellent before you go on a bus ride. The mozzies love to hang out under the seats and feast on ankles.
This might just be me, but I never grab a roll of toilet paper by putting my fingers inside the tube. Grab it first on the outside, then check the tube for spiders or other creepy things. Caveat: I have never in 20 years of traveling seen anything creepy inside a toilet tissue roll.
To get your check at a restaurant, use the international charades motion of signing your name in the air. It is understood everywhere.
To hide sweat marks in hot and humid travel destinations, wear black, white, or patterns!
Use the word "maybe" to ask a question. This works pretty much world wide. It's especially helpful in countries with tonal languages because raising the tone at the end of a sentence to ask a question as we do in English doesn't always translate. "Maybe there is bus tomorrow?" "Maybe rain today?"
Wear your heaviest and bulkiest items (mainly shoes) when flying so your luggage weighs less and is smaller.
When applying for a US passport, you have the option to select a 52 page passport (as opposed to the standard 26) at no extra cost.
When taking a taxi, agree upon the fare before you even get in the car. Some countries use a standard meter system but most do not.
When you arrive in a new country, jot down the local emergency number. Even if you don't have a local SIM, someone you're with might and it's better to have it and not need it than the other way around.