I find the amount of interesting things I have to say correlates strongly with the amount of quality reading I do. It doesn't have to be related to what I'm saying. Like I've been inspired to write about technology by reading Herodetos.

I think it's useful to view your mind as a garden. If you plant nothing then all you'll grow is weeds. If you get rid of the weeds and plant interesting ideas by engaging with new ideas, then it will grow interesting ideas on its own.