This means that there is one more piece of advice:
"If your post didn't hit the front page in the first attempt, try again later".
I've also re-posted some things that others have posted (and others have re-posted stuff I've posted).
I think the key thing is to not spam. I share other people's posts mostly. 90-95% of my posts are what I find that I think the community might be interested in, as opposed to posts of my content.
If you don't promote cool stuff you write, who will?