Some kinds of writing seem as natural and effortless as speaking – for example, a letter to a close friend. For some reasons why writing a short column is more difficult than other kinds of writing are:
Short columns lend to be about subjects that we do not know very well; we have no personal experience to draw from.
You have to ask yourself what information your reader is interested in knowing, how much details is appropriate, how to organize your short column.
When we write a short column we may not know our reader very well, we will never meet.