Chances are you will be installing into GIB (plasterboard or drywall) as joists are never where you want them!
This isn't a showstopper in fact, it's pretty simple. Let me walk you through how I do it.
1. Decide on placement and determine your ceiling type. Most NZ ceilings are 13mm GIB (plasterboard/drywall).
2. You can tap, use a stud finder or what I do is drill a thin pilot hole (the same size as my eye screw (ceiling hook) diameter - EXCLUDING the thread. This is important, as the thread needs something to grip into so don't make this too big). If you drill into wood, continue with a wood eye screw install.
3. If your drill drops through the GIB or plasterboard, then proceed with a hollow wall anchor install. This will require a bigger diameter hole. Follow the instructions of the anchor you have chosen. I used the Toggler TB anchor.
4. Drill anchor hole, insert and 'pop' anchor so it opens up inside the wall.
5. Insert eye screw (make sure the diameter of this screw fits your wall anchor specifications). Clip on your hanger.
6. Add plants and remember to look up and enjoy!
Resources:
Toggler TB hollow wall anchor - Mitre 10 link