Drive there by car from Invercargill.
Bluff is a small place. Find a place to park along the main street or at the viewpoint at the south end of town and walk.
Bluff is where you can take a ferry to Stewart Island. The ride takes about 50 minutes and can be very rough if the wind is strong, which it often is.
Good views can be had from lookoff hill, a short drive or hike up from the main street in town. On a clear day, you can see Stewart Island as well as a couple of other minor islands off the south coast.
Hike the coastal walkway from the parking area and viewpoint at the south end of town around the southern point.