There are some unwritten rules when it comes to you writing an op-ed.  You may not go by all of them but, they are all very helpful when wanting to write one well. 

One unwritten rule is when you write the article, make sure that what you are writing about is relevent to what is happening now.  Don’t write about something that happen even one month ago if it’s not effecting anything or anyone now.

Another “rule” so to speak is making your article persuasive, or argumentive.  These editorials are opinions, you want to persuade people to agree with your opinion it’s basically the point of writing an op-ed.  Sometimes the op-ed might cause arguments, but not everyone will have your same opinion so that is why.