Any chance you could link into some material how to do this correctly? So far I've been sticking to tracks and they were good enough for me. But it does feel like I should go off-road. I've been to a walk with a meetup group, but that wasn't proper bush either.
Your best bet is to find a local tramping club, each area has different challenges. Beyond that DoC has a good set of tips http://www.doc.govt.nz/safety