Flying into Changi
Almost everyone arrives through Changi Airport, consistently ranked among the world's best. It has four terminals plus the Jewel complex, and is connected directly to the city by the East West MRT line — the ride into town takes roughly 30–45 minutes depending on your destination and costs a few dollars, far less than a taxi.
Crossing overland from Malaysia
The Causeway (to Johor Bahru) and the Second Link both carry road and rail traffic between Singapore and Malaysia. The new Johor Bahru–Singapore Rapid Transit System cuts the crossing to a few minutes by train; buses and cars cross too, though the Causeway can back up badly at weekends and holidays.
Visas & the SG Arrival Card
Most passports enter visa-free for stays up to 90 days; a shorter list of nationalities need to apply for a visa ahead of time. Regardless of visa status, every visitor completes the SG Arrival Card online within three days of arrival — it covers both your entry declaration and a health/customs declaration in one form.
Fill in the Arrival Card a day or two before flying, not at the gate — the form occasionally has brief outages and you don't want to be racing it during boarding.
Customs, on arrival
Duty-free allowances are tighter than many visitors expect, particularly for alcohol and tobacco, and Singapore enforces them. Chewing gum for personal use is technically permitted in small amounts despite the reputation; bringing it in commercial quantities is what's actually restricted.