Whenever I get an idea of a topic I could write about I write it down. Even though I write daily I have managed to accumulate rather long list of potential topics. There seems to almost always be something to write about.
On the rare days I can't come up with anything I then resort to this list. Sometimes it's hard to remember what I was thinking about writing some of those few words I have scribed there. Other times I find topics that feel oddly familiar... I feel like I have written about this already.
Some of the topics I've actually written about. The ones that I just forgot to check out from the list. Others I might have written even without looking at the list, either coming up with the same idea again or just remembering it just because I had written it down. I have also found myself writing down the same idea over and over again. Even if I write it once and remember to remove it from the list there are still all those other copies of it lurking somewhere down the list.