The in your face answer to this is to of course pay down expensive high-interest debt first, credit cards and personal loans spring to mind. These can sit racking up 20%+ interest, a rate of return you will be hard-pressed to beat through investing. Therefore it makes sense to get rid of these as fast as possible.
Your student loan is the next thing that jumps out, this I would say don’t bother paying off any more than you need to, just let those repayments dribble out of your pay packet each week. It’s interest-free (so long as you stay in NZ) and is probably the best deal on money you’ll ever get. In fact, if you’re still studying here’s why I maxed out my student loan.
Once you’ve paid down your high-interest loans it starts to get a tad difficult, if you have a mortgage then you might consider pouring more into this, it is a risk-free return. Every dollar you pay down the principal reduces your overall interest. But with today’s low-interest-rate mortgages you could consider investing that money instead. You could well see returns much higher than your mortgage interest rate, making this a better investment for your money although a significantly higher risk one.
This is where you really need to consider what your risk appetite is and do some number crunching to work out if this is the right course of action. Investing money rather than paying down the mortgage may end up being a better investment, but it carries a much higher risk.
In regards to saving you should look at regularly putting a small amount away in a high-interest savings account to use in case of emergencies. I have $3000 stored away which I can quickly access if I ever need it. I built this by simply setting up an automatic transfer each payday for $40 per fortnight. You should really only start this once that hefty consumer debt if out of the way.