Getting to do something you have never done before.

Thought it would be interesting to here what you all think is the best way to move up or over in your area of interest- or how do you ethically get a job doing something you haven't ever done before, whether it is cutting long form or recording ADR or whatever.
One editor I know says it is all about lying at the time of the interview, but making it true when the gig starts.
What say you?