I love metal. The sub-genre is irrelevant if the music is good.
Generally, my reviews will consist of:
An opening statement
A description of what the album/single sounds like, generally speaking, with a ranging number of comparisons and details (along with the occasion music-related rant).
A "Scoring Summary" (though sometimes my score will simply be based off of how much I enjoyed and/or a rough estimate of how good I actually think it is, so I won't bother dedicating an actual section to it)