1. Spend time reading article;
2. Upvote and comment on the best ones you find;
3. Comment on the comments, join the conversation, start a new one;
4. Follow and don't hesitate to make it known;
5. Do not antagonize anyone, just ignore if you think a post does not bring anything to the community
6. Write not too short and not too lengthy posts, at best divide it into series.

That's all i can think right now :)