What does a good Haiku have?

A good haiku has three lines, and is most likely about nature and things like that.
It doesn't have to rhyme, either.
GOOD example: The tree, a beautiful creation
In the fall, leaves leave.
The tree, oh tree, a beautiful creation.
Also, in a Great, not good, haiku, the last line can be like the first.
BAD example: My Iphone was ringing, which was annoying.
I told my Iphone to SHUT UP.
Sadly, i was on the subway, so people started staring.
Don't have a haiku have stuff about electronics, items, etc. You know what I mean.
It should be about nature and earth and everything. not society. That's just my opinion! Hope this helps! (By The Way, I just made up these haikus i did NOT NOT NOT steal them. If there is another just like them, i promise i did not copy them!)