Hong Kong may have one of the cheapest transport systems of any major, developed-world metropolis, but the temptation of another quick cab ride always beckons - and, added up, it can eat away at your bank account.
You'd take a bus if only you could work out the convoluted routes. Well, now a number of free smartphone applications are here to help. Simply let your phone track your location, type in your destination, and an app will recommend a number of cheap public transit options.
The Transport Department app is decent and works on iPhones, but it's somewhat unwieldy and offers only simplified bus and tram information.
Android users get a couple of better options: StudioKuma Bus Info includes all major regular bus and tram services, as well as giving you detailed pricing and route-change information. But I much prefer HK Explorer. It uses Google Maps to pinpoint locations, offers detailed pricing and journey times, and is the only app to include the faster green minibus routes.
Your Octopus card offers numerous savings, but there are always more advantages. You might have seen those stand-alone Octopus card machines around town - they're part of the MTR's fare saver programme. The one on the Mid-Levels escalator gives you a HK$2 saving every time you swipe your card on the machine.
A number of major banks have partnered with the MTR to offer credit and ATM cards with Octopus capabilities, and signing up saves you money. Citibank's Octopus-linked credit card gives you HK$200 in Octopus cash as a welcome offer, and Dah Sing's cash card gives you a 2.5 per cent rebate on every top-up.
But while using your Octopus is a good idea in most situations, it isn't when you travel to the airport. For the Airport Express, make sure you and your friends buy physical tickets together - a four-person one-way ticket from Hong Kong Station to the airport, for example, costs HK$250, saving you HK$150. For even bigger savings, try taking the bus - the journey from Tsim Sha Tsui costs as little as HK$23.
And when you return to Hong Kong, if you're planning on buzzing around the city, there's no reason not to buy the tourist-friendly Travel Pass. For HK$220 you get a single Airport Express journey and three days of unlimited travel on all trains in the city.
There are also means of transport that aren't strictly legal, but which I must mention in the interests of full disclosure. People travelling in groups often opt to call a "man with a van" instead of taking multiple taxis - each van can fit up to 10 people and costs as little as HK$50 for a cross-harbour journey.
And finally, if you must take a cab, consider one of the popular "discount taxis" - drivers who charge fares reduced by up to 40 per cent if you hire them regularly for fixed journeys. Again, it's not legal, but the government is considering options to make it legitimate, so consider getting in your cabbie's good books before all the best spots are taken.