It is in fact not easy to collect the 100.000 miles, which are required for a free return flight from Europe to New Zealand or Australia, but it is possible. Earning more miles, even without flying, isn't too hard at all. Whenever you have to spend money, ask yourself: is it possible to get miles for that? It is indeed more often than one would imagine. If you are an employee, who has to make many business trips, you can benefit from that a lot. You have no official right on the bonus miles for the business flights your company pays for (german law). Some companies don't care about, but please ask them beforehand. If you have to pay upfront for some other expenses like hotel, rental car or whatever, this is your chance for many miles!
500 miles for free
Subscribe to the Miles & More Newsletter NOT during your announcement, do that AFTER your first regular login to your account, so you ensure your first credit of 500 miles.
For each lease at the big car rental companies in germany (Sixt, Europcar, Avis, Hertz, Budget) you get regularly 500 miles - no matter how long or how expensive. On promotions you can get much more miles.
at all Miles & More hotel partners you will get miles for your overnight stay. Courtyard Marriott for example gives 500 miles - no matter how long or how much, similar to the car rentals.
Lufthansa Miles & More Credit Card
The best of all in my opinion: you can earn miles rather with every money you spend. You have to refuel the rental car before return. Maybe you have to eat or drink sometimes, I don't know. You may need clothes. You may have to pay the hotel stay or car rental upfront. Everything you can pay by credit card brings miles, if you use the Lufthansa Miles & More Credit Card. Even for expenses - who cares about, in which way you pay them? There are promotions from time to time for this Credit Card: bonus miles for ordering the credit card, reduced fees for the first year. Do not just simply order, ask for promotions, ask for special bonus.
There's another bonus system in germany called Payback, where you can collect points for buying food, refuel your car, buying in a hardware store, in a drugstore, in a bike store and in many well known internet shops. The collected points can be transferred 1:1 to the Miles & More account, when you have collected at least 200 Payback points. Watch for special promotions and you can earn more.
This list is by far not complete. Promotions appear very frequently. Even if you don't get enough miles for the free New Zealand or Australia trip, a free ticket inside your region is easy to get. Inside Europe for example starting from 10.000 miles.