I find the idea of writing non-original content to be pointless though. If it isn't original then someone else has already said it and they have probably said it better.
I think you will be very surprised as to how much people don't know. The regurgitation of information isn't a byproduct of laziness; it's a direct result of two things.
1. People don't like to read.
2. There is far, far too much noise on the web, as it is.
It may have already been said, but I'll guarantee you that only a small minority ever read it.
You could talk about what it is that you know. What it is you hope to know. Not every developer takes the same road. If your intent is to eventually position yourself as a domain expert, the rest should write itself.
You could write design descriptions of your projects. What decisions did you make, and why? What was the purpose of the project? Why did you write new code instead of using something that had already been written? Etc.
You're not going to get better if you don't get started.