NO CASHFLOW !!!!!!

Are any of the properties within reasonable commutes to a defence base?  If so, maybe you could try and rent directly to the defence force?  The Aussie equivalent is http://www.dha.gov.au . 

Are any of them close to universities?  If so, contact the uni housing department.  They might be able to get you a tennant for the next academic year.

Have you taken a look at the rental vacancy rates in the area that your properties are in?  Is the vacancy rate high anyway, or is it low and sadly your properties are the ones not getting rented?  If it is the latter, try looking at how your properties look compared to the ones that get snapped up quickly.  For example, is the kitchen a darkish environment with brown cupboards that could be brightened up cheaply with some white paint?

Not that it helps a great deal rhetrospectively. But I think it really comes down to ensuring the areas and properties you target during the research phase have a balance of both strong rental yields and capital growth prospects. Ultimately whilst the growth allows you to access equity to buy more property it is the net yield and thus cashflow that enables you to stay in the market and to keep on buying.

Given that you have 11 IP's already you probably know some of the other more obvious tricks. But just in case.

– Make sure you are claiming all available depreciation, and filing a tax variation to keep the money flowing.
– Charge market rent.

Also as JacM briefly mentioned make sure you assess the oportunity costs of improving each of your properties so that they maximise their appeal to each properties relevant demogaphics.

I.e. I recently purchased a unit for $481,000 having been told it wouldnt really appeal to investors as I would be able to achieve a weekly rent of just $425 per week. A rental yield of 4.59%. I knew from assessing the competition that due to the area appealing to a more affluent  and time poor demographic that units which were fully modernised were able to attract a premium in their achievable rent. As a result by spending just $22K on renovations, I have now just been able to rent the property for $550 per week. A yield of 5.68% on the total investment.

Hope this will help in the future.

It sounds like you should be considering buying cashflow positive properties. If you are negatively geared over a portfolio with interest rates as low as they are right now in NZ, there is something wrong.

P.S. NZ has basically no defence force, so count that suggestion out.