“Temporary” is a tricky term. It can mean anything from days (say if you’re a rock star), up to a few years (say if you have a real job). As a result, there are lots and lots of different kinds of visa.
But essentially – as a migrant – you’ll get a visa either because:
Depending on your temporary work visa you may be able to apply for Residency, either straight away or after a period of time has elapsed (there are lots of variables, so it’s best to talk to an advisor about where you stand on that).
In addition to the employability factors, New Zealand Immigration considers your health and your “good character”, recognised initially in the lack of any criminal convictions. So, the best game plan for a successful visa application will be get skilled, be healthy and stay out of trouble.
If you want to be supported and have more certainty around your outcome use an immigration agency. If you are offshore, go to MoveList.com to find immigration and visa agents that can help you apply for residence.