I find that the longer I spend in the audiophile hobby, the more cynical I become of reviews (especially when half the review seems to be an excuse to show off photography skills and making the product *look* good).
When I look up reviews on a site that has a rating system (like Amazon), I always start with the middle to find those who try to present all sides. I then filter through the good and bad reviews looking for the same arguments shared by those in the middle, and how their experiences differed to warrant the change in rating.
I used to post more on headfi, but have been a bit disillusioned with their rigged rating system there.
To me there's no real formula for a good review. Me personally, I write mine a bit like high-school-essay or science paper format. Start with an intro and state the main points (or a straight up TL;DR) and my relevant gear/experiences. Follow with the body and main analyses. Cap it off with a summary because some people only read the ending and didn't see my tldr at the beginning. Then I shove a whole bunch of pictures into the second post because I'm not going to be fancy and format my review to look like a gorram advertisement.
When I post impressions, I try most of the time to give it in relation to another product so people can draw a valid comparison. I have enough experience and confidence in my abilities to know what I'm saying, but not many people actually know my reference points so describing audio to strangers is really a shot in the dark for most. On the rare occasion that I recommend equipment that I have have not heard, I will preface the statement that I have only read or heard about it, or I am echoing the sentiments of a friend who's judement not only do I trust, but we in fact have shared experiences on similar gear so I know our reference points are the valid.