For Head Hunting, you need to be creative in your approach and be able to use your network and references well.
For instance, I have an opening for Manager HR in an FMCG, I know that there was a person,A, at some time working with another FMCG, say Pepsico. All I know is his name and his tenure with pepsico. His nos. have changed and I am not able to get in touch with him directly.
There is another chap,B, who also worked in pepsico at the same time as this HR guy.
Now I get in touch with B, asking if he is still in touch with A?
He tells you that he is not in touch but he knows that A had joined Wrigley's(say).
Now you check if you know someone in Wrigley's(any department)
Yes--- You call your contact in Wrigleys and therefore reach A.
No---- You call Wrigley's Boardline, and make up stories so that your call is put through and you reach A.
Remember during a cold call on the board line, you have to be very sure of what you say, because generally any anonymous calls are transfered to HR Deptt as a retention tool. Any HR deptt would not let any one trap its talent.
Also there could be linked to industry mapping.
Hope it was useful.
Best Regards