I'm sure you all know this, but it's still worth repeating.
Whenever you post an essay, try to review at least 3-4 essays from the unanswered list. At the end of your critique ask the author of the essay to review your one in turn. There is a good possibility that at least two will critique your essay.
This will also make you more noticeable to other members, thereby increasing the chances of your essay getting reviewed.
So don't stand there waiting for a moderator. Get involved!!
P.S. When I say review, I mean a proper critique and not just 1-2 lines...the way you'd like your essay to be reviewed.