MTR Payment

My experience, Advices 

1. I learn from my experience bring new 100 dollar bills  for exchange cash because if you use the old dollar bills you will get lower exchange rate and cost some fees.
2. have a credit card or debit card. Have a credit card that has an pin to enable you to take cash out of an ATM.
3. if can, open a bank account, but many doesn't allow because don't have HK ID, i try more than 10 banks.
4. have at least 200 HKD cash before arriving to Hong Kong because to open an octopus card. you can use credit card to in to Metro station and bus .
5. start to apply for the student octopus card because you get a student price for the mtr , but i didn't apply because it was too late.
6. Get a Sim card for hong kong phone number  to activate app accounts. 
7. Have a Visa , so can travel everywhere 
8. try get an HK ID, but unless saying more 6 months.