I just spent three whole weeks on vacation, doing exactly what I wanted to do (museums, food, wine, start-up conversations with dogs in the street).

It was also three whole weeks of spending, and trying not to spend too much and considering each potential purchase's bang for the euro. Sticking to a budget, and blowing the budget, spending wisely and flushing money down the proverbial toilet.

And when the latter happened, trying not to let it ruin my whole day.

In three weeks, I was reminded over and over again how many ways there are to be scammed, fleeced, gouged, fee'd and taxed. I remembered that the kindness of strangers does not extend to them lowering their price just for you. I realized that prices are ridiculous because the market will bear them. You have to decide what's important to you when you travel, and try to get it for the most reasonable price out there.

I also was reminded that there are plenty of ways to save: There are cheaper alternatives or ways to get discounts for almost anything, from entrance fees to transportation. You can even get money back on that extravagant pair of boots or replacement lens you just had to buy.

I'm pretty good, by now, at finding alternatives and knowing where I can save. Then again, you can't go three weeks (longer, if you count the planning stages for a trip) without getting your wallet walloped in some new or unfamiliar way.

I figure by putting down some of the more widespread ways we travelers waste money, it'll help me remember — and maybe a bell will go off for you next vacation before you toss those bucks down the drain.

THE TIP-OFF: Americans are trained to tip. The etiquette, the percentage, those details vary, but when the waiter delivers our bill, we knee-jerk start figuring what to add on to the total for the server. When you're out of the country, however, you should check if you even need to leave a tip at all. Tipping customs vary wildly around the world — from Japan and South Korea, where it's frowned upon, to China, where it's usually considered insulting, to France, Switzerland, Finland and the Czech Republic (to name a few), all of which have laws requiring the tip/service charge be included in the final cost. Usually you can find a clue about the tipping question on the bill: "service compris" in France; "servizio incluso" in Italy; "Servicio no incluido" in Spain.

Unfortunately, you may not find anything about tipping on your bill. There's also the matter of obfuscation. I've been in hotels here and abroad where room service tabs will state that "Service is included," but there's still a line labeled "Tip." This remains somewhat mysterious to me. Some use the words service and tip interchangeably. Others make a distinction: "Service" usually refers to a fee for catering a dinner or serving a large group; tip is what you give the waiter personally (though some tips are shared, and some law-required tips never make their way to the servers at all).

STAND FOR FOOD: Get a crêpe, a baguette sandwich, a slice of pizza or a falafel at a window-service eatery or food stand, food truck or kiosk. The locals do. This is best for lunch, when you're in the midst of seeing and doing things while everything is open. It's also best in places where you're fairly certain you won't get sick from whatever's in the sandwich.

MAKE BREAKFASTS LAST: If you get breakfast with your hotel room, eat and eat and (can I say this?) grab some for later, too. In some cases, it pays to upgrade to a better room. I paid an extra 30 euros a day for a room with a view at one hotel. With that, I got breakfast, all the coffee I could drink all day, and free Wi-Fi. Worth every penny, just for the view. And they treat you nicer.

DIAL DOWN DINING: Hit restaurants in less tony parts of town. In fact, eat where the universities and colleges are. I ordered vin chaud (hot mulled wine) whenever I ate out in Paris, and it always looked the same, but cost anywhere from 3 euros (about $4.05 at recent exchange rates) in a part of town with a lot of students to 7 euros on Rue du Faubourg Saint-Honoré — where it was lousy, by the way, and the service was abysmal.

ATM NICKEL AND DIMING: Look at your credit card and bank bills when you get back home. Besides the purchases you make, look at the ATM withdrawals. For a while, I noticed a $1.50 here, and $2 there, all of them explained by "fee." Most bank ATMs in Europe don't charge a usage fee, but indies — run by companies like Travelex, Euronet or Forex and often found right beside the bank ATMs, do charge a couple of euros for each use.

Many banks are similarly waiving the international fee. (Check out sites like www.nerdwallet.com for current card fees and comparisons). You'll still get hit with the 1 percent fee that Visa and MasterCard charge on international transactions. Another easy way to avoid ATM fees is by banking at a global institution like HSBC, which has branches in many countries.

GETTING-AROUND COSTS: Taxis may seem like the most convenient and civilized way around town. Sometimes they are, but metro systems are efficient and traffic-proof. And from a European airport, especially, the magic word is "shuttle van." Book ahead, and get a shared van, not a private one.

CANCEL THAT: Maybe when you were planning your trip, you found a hotel that looked good, so you booked it. Then you found another one that was even better, so you booked that instead. If this is you, beware: Cancellation policies are getting as nutty as airfares, with variables galore about how far in advance you need to cancel to get a 100 percent refund. Hoteliers aren't as understanding as they once were when it comes to no-shows. Cancellation policies are enforced — you could say ruthlessly, a word not often applied to the hospitality industry.

GET A BREAK: Ask for AAA, AARP, student (bring your ID), military and family discounts. Most cities have a city-pass card that usually saves you money on attractions, public transportation and shopping. Some passes — or museum/attraction passes — allow you to skip the lines and go right in. The big discount? Free night at the museum. Most museums have one night a week when they don't charge a thing.