Hong Kong Travel Tips
Taxi
When paying your fare, it's good practice to get a receipt. Also, watch for any dishonest behavior about adding fees at the end or any arbitrary charges the driver may introduce. Passengers are responsible for poll fees that the taxi incurs while going through tunnels and $5HKD per bag for luggage in the trunk is normal. Should you encounter any difficulties or have a complaint about a taxi driver, the HK government has setup an official complaint form here.

Scam Alert: When exiting a taxi, make sure the taxi window is fully shut before shutting the door or exit through a door where the window is fully shut. In mid 2014, there was a growing scam that involved taxi windows breaking upon being shut with a window lowered a few inches. The taxi drivers then demand as much as $2000 HKD ($258 USD) for the damage.

MTR
When approaching the turnstile, have your Octopus card ready so you can quickly pass.

When riding the MTR subway, take off your backpack and carry it by the handle for 2 reasons.
1) It will make it easier for you to move around the train car during stops.
2) You won't expose your bag to thieves.

Pro-Tip: Get a Pac-Safe bag. Their bags made with ExoMesh are perfect for traveling and have a steel wire mesh built into the fabric to prevent loss from having your bag fabric slashed with a razor. Check out the other security features here.

When boarding, wait for people to exit before boarding. It will make the boarding process a lot easier.

When exiting, if you are near the opening door and the train is full, exit and immediately stand to the side to let others behind you exit. This will get you out of the way of traffic and you will be the first to board once people have exited.

When riding on the escalators, stand on the right and walk on the left.