...I start writing a few chapters or only one.
And then later, I don't write the rest and the series ends up unfinished...
Even though there are a few fanfic series that I have finished like the Super Junior fanfic series that I wrote as a teen on a fanfic website and also the He Whispered To Me which I wrote on this forum before the revamp (and I have kind of wanted to write a similar fanfic).
I most often prefer writing oneshots and then sometimes write a sequel if I want to.
And I do have some oneshot fanfics that are kind of connected to each others.
I remember writing some oneshot fanfics that all contained something that had to do with a pink rose. (and some of the fanifcs, I wrote afterwards, contain references to the pink rose.)
When I write original stories, I also prefer writing short stories.
There are times when I have wanted to write a novel, but it has always ended with me quitting.
I have a poem collection that I feel finished with, even though I guess it still needs some editing.