Travel Tips for New Zealand's South Island

Customs and bio-security are very very strict. The fact they call it bio-security is an indicator of just how serious they are. You will get fined if you try to bring in food or other prohibited items that you do not declare. They x-ray all bags looking for prohibited items.
Bio-security inspected my shoes. You can smooth your entry bay thoroughly cleaning any outdoor equipment you are bringing with you.

Watch for New Zealand's speed cameras. There's only seven of them on the South Island. Their locations can be on a pdf linked on this page. The one in Oamaru issues an obscene number of tickets. The locals undoubtably know the camera is there so the camera mostly serves to extract money from visitors.
Distances are deceptively long. As the crow flies, going from point A to point B might only be 40km but it might over 200km by road since there are very few roads over mountains and mostly one has to drive around.
Travel speed isn't all that fast on highways so plan accordingly. The speed limit is 100km and almost every highway I encountered is a two-lane road. It's common to get stuck behind slow traffic.
Driving is the left which the point of view someone from the US is the wrong the side of the road. I didn't have too much trouble adjusting. I found the more urban areas, like Dunedin, challenging.

I visited in April and the weather was quite chilly much of the time.
The west coast is temperate rain forest so rain is expected. If you haven't committed to a fixed itinerary, check the weather forecast at the beginning your trip and arrange your itinerary around the weather. I saw Milford Sound on a clear day and suspect its less enjoyable in the rain. At Fox Glacier, I saw basically nothing because of bad weather.
The eastern side of the island is much drier than the western side.

April is the low travel season and I didn't have any trouble finding accommodation without advance booking.
Because the weather is unpredictable in April, being able to adjust my itinerary was valuable.

Wildlife, Waterfalls, Fjords And Mountains - 10 Day Itinerary Around New Zealand's South Island -- This site has several very helpful itineraries for both North and South Island
New Zealand’s South Island -- Outdoor Photographer
Old Pier of Lake Wakatipu -- I've seen this called Old Glenorchy Wharf or Wakatipu Pier. It's a bit challenging to find. There's a debate as to whether in the age of Instagram posting precise location details is appropriate. In this case, I don't see this as getting flooded with Gramers as it's not all the interesting to shoot with an iPhone. A couple of hints in finding it: It's only visible (and barely) at that when traveling towards Glenorchy. There's a sign right across from pull out that says "Guest House + Art Garden" and has a fish on it.

Lonely Planet New Zealand's Best Trips -- This was the most helpful guide-book I used since it lays out road trip itineraries.

New Zealand is a pretty easy country to travel in. The people are friendly and it felt very safe to me. The biggest danger is a car accident.
I'm glad I went. New Zealand had been on my bucket list for a long time. However, it fell a bit short of my pretty high expectations. I'd heard many people talk about how scenic it is and this is true. However, I didn't get the sense of awe at the scenery I'd hoped for. The Southern Alps are just not on the scale of Rockies or the (European) Alps. If I lived in Sydney, where New Zealand is only a 3-hour flight, I'd no doubt make many trips. As long journey, it's a tougher call.