Many business travellers headed to Hong Kong also choose to visit nearby Shenzhen, which is perched on the edge of the Chinese mainland but barely one hour away.
Considered the heart of the Pearl River Delta manufacturing zone, Shenzhen is one of China's eight business- and trade-friendly "special economic zones".
There's no shortage of companies in Hong Kong which will shuttle you there by car, coach or minivan – your hotel's concierge can make the arrangements – but it's quite easily done using by train, using Hong Kong's MTR network and East Rail line and your Octopus card.
1. Head to Hung Hom MTR station
Hung Hom is at the city end of the purple West Rail MTR line, and just one station past East TST – which also puts it within easy reach of most hotels in downtown Kowloon.
2. Change to the East Rail Line
Hung Hom also shares a connection to the light blue northbound East Rail Line, and you probably won't even need to change platforms – just walk across to the other side of the same platform.
3. Catch the train to Lo Wu
East Rail Line trains are not as modern as those on Hong Kong's MTR metro services, and the train runs overground through much of its journey as it cuts north through the New Territories region, so there's a little bit of scenery.
After around 40 minutes you'll alight at Lo Wu (also written as Luohu), which is on the edge of the Hong Kong / China border and the most popular point for entering Shenzhen.
4. You are now leaving Hong Kong...
Follow the crowd through the exit at Lo Wu station and towards Hong Kong immigration.
This is where it can get a little tricky (and time-consuming): you'll want to veer right towards the 'foreign' lane, even if you have Hong Kong's e-Channel pass, as the sign-posted e-Channel lanes at this checkpoint appear to work only with the passports of Hong Kongers and Chinese nationals.
Keep your passport in your hand and be ready to flash the rear cover with its e-Channel sticker to any customs staff standing around to direct travellers. They'll direct you to the e-Channel lanes for foreigners, which is in the 'foreigners' zone at the far right side of the checkpoint.
When i visited Shenzhen it was a busy Saturday morning with was extensive queue for the manual 'foreigners' checkpoint but only one person staffing it, compared to a dozen e-Channel gates in operation and a waiting time of barely one minute.
5. Cross the border into Shenzhen (have your visa ready)
After passing through Hong Kong immigration you'll cross a footbridge over the Sham Chun River which marks the Hong Kong / Shenzhen border, and then line up for Chinese immigration.
Your Chinese visa or APEC Business Travel Card will see you through to Shenzhen. if you don't have either, you can apply for a single-entry Shenzhen visa just before the immigration checkpoint.
That process can take up to 30 minutes and costs ¥168 (A$34), and we've detailed it here.