The BTS sky train is a convenient way to get around. The fares start at 10 baht for a single journey.
It runs on tracks above the streets of this vibrant city. Take the stairs from street level to the station.
Go to a ticketing machine. You will find there a map that displays, how much the fare is for your selected journey. Also look for the name of last stop of this train line, this is important as you will see later.Press the button with the right the fare for your route, pay and receive your paper ticket.
Most ticket vending machines accept only coins. There are some machines that accept also bills, but only at selected stations. Day passes are also available for 150 baht. You can purchase them only at the ticket counters located at some stations.Go through the fare gate.
Next, take the stairs or escalator up to the trains. The system works similar to public transport in Europe, look for a sign that tells the name of last station of the line. This will show you in which direction which train will take you. Board the train. On the train they will make announcements about the next stop both in Thai and English. Get off at your designated stop and exit the station through the fare gate.
Some train stations are also connected to nearby shopping malls by a overpass.
There are currently 2 lines running through the city, you can use your ticket on all lines.
The government of Bangkok is still working on extending the existing network. E.g the trains don’t run to the northern districts yet.
Here’s a video by DiscoveryThailand, which explains the system pretty detailed.