This particular spot at Lake Pukaki (the same location is Mount Cook Poppies and near the Visitor Centre) has beautiful views over the lake and straight out to Mount Cook with some nice boulders in the foreground.
If you're lucky you might be able to capture a person walking along the shoreline for scale which really puts into perspective how big Mount Cook is.
You can park your car across the road in the carpark and carefully cross the road to the verge to where you can set up your camera or climb down onto the boulders. Take your wide angle to capture the whole scene (eg 16-35mm) and your zoom lens (70-200mm) for a compressed view of Mount Cook and the lake.
This spot will work well at both sunrise and sunset and I shot it during the day.