The fastest way to get to Liechtenstein is by flight to Zurich airport and then by train or by bus. But the cheapest one is, however, to use budget-friendly Air Belin airlines and make a connection flight in Berlin.
If you are planning to get from Zurich to Liechtenstein you can buy the entire ticket Zurich – Vaduz. It will include two journeys: the first one is by train going to the boundary town Sargans and the second one is by bus from Sargans to Vaduz. Buying a single ticket for each of these journeys will cost more.
Purchasing the Tageskarte is convenient and advantageous. It costs 5 francs and is valid for all buses running across Liechtenstein during a day. Thus you will be able to see several cities by making a stop at each of them.