We can get the exchange rate down by having a negative balance of payments with the rest of the world.

Unfortunately a negative balance of payment causes debt that has to be paid off!
The solution is to invest in large capital projects and infrastructure that will provide a return on investment.
We go into debt and get delayed payback over one or two decades (the return on investment gradually pay off our debt).  In the first decade our exchange rate will go down and we will stimulate our job market through a negative balance of payments.

The caveat with the above strategy is that we have to be smart when we select capital projects (investments).

The crazy thing is that the current New Zealand  government (John Key and friends) is doing exactly the opposite. The government is hiking up the exchange rate by signalling that we are going to sell our assets (achieving a good balance of payments, but destroying our ability to export).  As a double whammy the income from sold assets will go elsewhere, causing a negative balance of payments in the future.

The only way to have a healthy economy is to have one that produces, and for that we need infrastructure.