How do you choose parting line in injection mold

Parting line: This is the line created when the plates of the mold opened.
Parting surface: these are surfaces which use for assembly between cavity, core, slide core.

When you choose parting line and parting surface, you must care :
 + To push final samples out of mold easy.
 + Make core, cavity, angular core easy.
 + Appearance of final sample is the best.
 + Design gate, runner system easy, flow of material is best.
 + If sample have under cut. Check under cut area that  make slide core, angular core and to push sample out of mold easy.
 + The important dimenson don't cut parting line.