GETTING THERE: There are no direct flights from Washington to Zurich, which is about 75 miles from Vaduz. Swissair and Pan Am have direct flights from New York's Kennedy Airport to Zurich. Swissair also flies direct from Boston, and offers package tours that include Liechtenstein.

Rental cars are available at the Zurich airport for the 1 3/4-hour drive to Vaduz, although Liechtenstein is compact enough that you don't really need a car: You can see much of the country via train and bus.

A train to Sargans and Buchs, Switzerland, with connecting bus service to Vaduz, leaves the Zurich airport railway station at frequent intervals; the trip takes about 2 1/2 hours. A Swiss Holiday Card, allowing free passage on many buses and trains, is available for $115 (for eight consecutive days of second-class travel) or $99 (four days). It must be purchased in the United States and is available at the Swiss National Tourist Office. GETTING AROUND: Timetables for bus and train service within Liechtenstein are posted everywhere. There are a few small rental car franchises in Vaduz, but availability of cars is limited. Taxi service is courteous but expensive. WHERE TO STAY: The best hotel is the Park Hotel Sonnenhof, a short walk or ride from the center of Vaduz. This elegant, low-profile place is in a garden setting complete with indoor swimming pool. It has 29 rooms with bath; rates range from about $150 to $200 double per night, including breakfast, service and taxes. Less expensive choices include the Hotel Real, whose double rooms with bath run about $100 to $140 per night, and the Hotel Engel, about $60 to $75 double. Both are on the main street in Vaduz.

Those who prefer to stay in a quaint setting in the mountains might enjoy the Hotel Martha Bu hler in Triesenberg. Rates are about $60 per night double, including breakfast, service and taxes. There are also several pleasant private pensions, including Helen Hemmerle's house at Birkenweg 12, Vaduz, where the four guest rooms cost less than $40 per night double, with shared bath, including breakfast, service and taxes.

It is wise to book in advance; even in late September I found some hotels completely filled. WHERE TO EAT: Among the more formal establishments I enjoyed personally or got excellent reviews on from friends in Vaduz were, in descending order according to cost: the Real dining room, perhaps Vaduz's best-known restaurant; the Engel upstairs dining room and Restaurant Torkel. Outside the capital, my favorites were the elegant Restaurant Waldhof in Schaanwald, the Berggasthaus in Masescha (an unpretentious typical mountain eaterie) and the Wirthschaft zum Lowen in Schellenberg, a simple country inn specializing in native dishes.

In Vaduz, good spots for quick lunches or light dinners are the Old Castle Inn, the Hotel Engel street level tavern and the Cafe' Wolff. STAMP COLLECTING: Stamps can be bought at your hotel, but the full range is on display and available in combination packages at the store on the ground floor of the Post Office Building, across from the tourist office. Hours are 8 a.m. to noon and 1:45 p.m. to 6:30 p.m. Mondays through Fridays, 8 a.m. to 11 a.m. Saturdays. Collectors can also be notified regularly in advance of all upcoming new issues or automatically purchase them on standing order; ask for the proper form. INFORMATION: In the United States, Liechtenstein brochures and information are available at the Swiss National Tourist Office, Swiss Center, 608 Fifth Ave., New York, N.Y. 10020, (212) 757-5944.

In Vaduz, the tourist office is located at Sta dtle 37 on the ground floor of the Art Gallery. (The Sta dtle is Vaduz's main drag.) The office has a wealth of helpful literature, and it is also where you can get your passport stamped. Hours are 8 a.m. to noon and 1 p.m. to 5:30 p.m. Mondays through Fridays year-round, and 9 a.m. to noon and 1 p.m. to 4 p.m. Saturdays, May through September.

There also are tourist offices in Triesenberg, Malbun and Schaan.