This advice is not given from my personal experience, as I am essentially a fiction writer. However, last week, I attended a panel for freelance writers, sponsored by the National Press Club and the Society of Professional Journalists. (No–I am not thinking of defecting to a career in journalism, but it is interesting to learn about everything.) This particular panel was on what magazine and newspaper editors look for from freelancers and much of the process seemed more or less similar to what editors and agents say at these kinds of forums about fiction. However, one of the panelists, Jenny Rough, suggested a number of pointers for writing good personal essays (presumably for mainstream consumption) that I think worth sharing:
1. Use a conversational style;
2. begin with a good lead (an obvious point; but she noted some examples: (a) an anecdote; (b) dialogue; (c) beginning in the middle (in medias res (?), and circling back to the beginning;
3. in the body of the essay, alternate between scenes and narration; and
4. take an experience that is personal and make it universal so that the reader gains an insight from it. (There should be moments of insight as the essay moves along.)
I think number (4), in particular, is good advice for writing fiction, too.