When I first started out, I was over thinking what to post. I guess I feared that some of the things I wanted to talk about wouldn't be considered worthwhile to people, but then I realised that it's simply not the case as long as you can demonstrate some form of effort going in to the post.
I am trying to spend as much time as possible commenting on other peoples' posts at the moment. It's seen interaction on my own stuff increase, and I'm now able to power up whatever amount of Steem I earn per day.