For approach sit on the left:

http://www.cad.gov.hk/english/pdf/noi1.pdf

For departure the choice is less clear:

http://www.cad.gov.hk/english/pdf/CLK_dep_track.pdf

Which direction you come in from depends on the wind. Generally speaking, in winter aircraft will land/depart from 07L/R and in summer they use 25L/R.