Public Transport :

Before arrival, check online or in your guide book if there is convenient public transport to reach your destination. It's better to have with you a credit card AND coins and banknotes.

 

Taxis :

If you intend to hire a taxi : many countries in Europe and North America have taxi-meters, so it's quite easy.

In some others countries, you have taxis with a taxi-meter but the driver refused to start it because you are a foreigner and give a flat rate obviously more expensive than the normal rate. Sometimes the meter is hidden under a cap or a clothe.

Also in many countries, there is no meters and the best is to check before arrival the distance between the airport and your destination in order to guess if the offered rate is fair or abusive.

In many cases, before departure, you can google "taxi rate airport to xxx city". It can give you an estimate of the fare.

Sometimes you can also order taxis online which will wait for you.

On internet, avoid the companies which resell taxis in all countries as they take a huge margin on fares. It's better to book directly with a local company.

 

Uber and other similar companies :

in many countries you will find such offers and it might be a good idea to book them in advance.

But in India, for instance, there is Ola taxis you can book in advance but unfortunately you need an indian phone number (hope it changes) so it's difficult to book it before your arrival but for your next fares, you can buy a local sim.

The online transport offers are evolving very fast so it's interesting to google to find such companies which have reasonable rates.

When you are a tourist and in a country where there is no taximeters, it's a good idea to book, even at the last minute, a car on an app like Uber, Grab... (not available in all countries) or on local apps specific to the country. The price can be better as, without taximeter, some taxis are abusing tourists with high rates.

 

Fake Taxis  :

In some countries, some guys without any licence are trying to catch customers in airports or train stations and they will transport you with a private car. Avoid these guys : a real taxi has marks on the car with the taxi company name and a number, also a meter in many countries.  Most of the times, it will be more expensive and they don't have any professional insurance. On top, in some countries, it can be dangerous.