What is the best way to get to Rambler Oasis Hotel from HKIA and vice versa? Thank you. :)

Well, upon landing, there is no direct public transportation that can take you to the hotel.
So take bus no.A31 to get to Cheung Ching Bus Terminus. Then transfer to bus no.88F and arrive at Rambler Crest. After arriving, walk south around 180 yards (150 meters) to find the destination. The whole way takes around 45 mins. It costs 22.3 HKD per person.

About the return trip, you are suggested to take bus no.A31 at Ching Tao House Cheung Ching Estate and arrive at the terminal building directly. It takes around 35 mins. The ticket fare is 18.9 HKD per person.