You typically only barter in markets with individual owners. Proper shops, eateries, and grocery stores have set prices. But in the markets and souvenir stalls you can try your hand at eking every last penny out of your deal. Sometimes if you're not sure if you should offer a lower price, just ask "better price?" They'll certainly let you know if the price is non-negotiable.
For taxis, you definitely need to bargain the fare if you're not using a meter. The best thing to do is get info ahead of time from a local or by searching online so you know what the price should be. Stick to your guns. Taxi drivers can be hard core about trying to way overcharge tourists.
DO BARGAIN FOR
tours
souvenirs
taxi fare
fresh produce and meat
bike rental
budget lodging
anything being sold on the street
DO NOT BARGAIN FOR
public transportation (i.e. bus & train tickets)
restaurants
mini and super markets
anything with a written menu
(most) food carts
Don't feel badly about doing it
In countries where it's expected, it's more like a sport; a fun game for both parties!Language isn't usually a problem
These people are experienced at this game. Many a negotiation has been made strictly by using a calculator. They'll type in the price they want, then you can feel free to type the price you want. Back and forth, back and forth, until you come to an agreement or a stalemate.Learn the local numbers
If you can't read the script used in the local language, at least try to learn the numbers. That way if a price is advertised for the locals, you will be able to read it and know what the price should be. Because as a tourist, that price will be ignored and they will quote you about 3x that when you ask.Sneak a peek at what the locals are paying
If you can manage to see what a local is paying for something, then you have a good solid target number to go for. You won't likely have a local buying the same souvenir you want, but they might be buying the same bag of oranges you want, or cold drink, and it works really well on public transportation (which is not usually a bargaining game, but a challenge not to get overcharged). It can be a bit difficult to keep an eye on the money being exchanged and recognize both what's being paid as well as the change given in the foreign currency.Learn the local words for "how much?" and "expensive"
That will give you a slight bit more respect in the game.Always remain good natured
You will want to hold your ground, but there's no need to get angry at any point. A little chuckle at their opening offer is acceptable.You can usually get something for about half of whatever they ask
So make your first counter offer accordingly; like maybe 1/4 or 1/3 their starting price. Even locals have told me that 50% is the target for them!Buy more than one
Buying more than one is a great bargaining chip. You can ask up front "how much for 3 of these?" but it's better to hold off. First ask the price for 1, then haggle down a bit, then bring up buying 3 of them. The low price becomes much easier to get to at that point.
This goes for lodging too. Ask the price for one night, then get the lower price for multiple nights.