The local transit has an app you can preload with rides.
Frenchman St for the music.
Stare at the mighty river, and be amazed at the thought of the amount of water that goes by every second.
Photograph doors and courtyards
Get a cup to go
Attend Sunday service at St. Augustine in the Treme
Catch a festival - there is something going on all the time
See music at Tipitina's
Oh, forgot you wanted to do some photgraphy...
Source: only two short visits, sadly