Ho Chi Minh City Airport to the city:
When exiting the international airport terminal, turn on your right and look for the bus station. Get on the bus 152, fare from the airport to Pham Ngu Lao area is about 5000 dong as of November 2014. The ride is about 45 min to an hour with traffic.
There are many stops on the journey, but if you’re heading to the backpack area of Ho Chi Minh City, alight at the terminal (Ben Tan market). From there you can easily walk to the backpack area namely Pham Ngu Lao.
City to Ho Chi Minh City Airport:
Similarly to above, to get to the airport the cheapest way is to use the public transportation. From Pham Ngu Lao area, walk to the Ben Tan bus station find across the Ben Tan Market.
There take the bus 152 direction Tan Son Nhat, which is the name of the HCMC airport. The ride is about 30 minutes with no traffic, and the first bus is at 6am. For very early flight, taxi is a better option. The bus terminal is the international airport, the stop before is the domestic terminal.