Review is a very specific kind of writing – it is supposed to give the reader an impression of something you have experienced without having to experience it himself. Quite naturally, it means that a review should transfer a lot of information in as few words as possible, and achieving this requires expertise and practice.
Reviews may be written on a lot of things: books, music albums, concerts, restaurants, videogames and so on – name something people may be interested in and you may be sure that there are reviews on it. The principles of writing a good one, however, are more or less the same no matter what you are writing about.
First of all, you should understand what a review is and what it isn’t. You shouldn’t retell the contents of the book or a movie or enumerate its characteristic features – you may mention something of the kind, but it isn’t what constitutes the basis of a review. What you should provide is a critical evaluation of the subject matter that gives reasons for it being exactly what it is. You should make your reader believe that your opinion is competent and useful, make him believe that your opinion is enough for him to decide whether to deal with the thing in question or not.
Secondly, no matter what you are reviewing, make sure you always know what you are talking about. Not only read (watch, play, visit) what you are writing about, but make some research. There is nothing more embarrassing than to make some obvious mistake while speaking about something you are supposed to be an expert at.
Thirdly, be as objective as possible. Sometimes you have to speak about things you have strong preconceptions about, and you should be able to fight the urge to ridicule something you hate just because you hate it or praise something you love just because you love it. For example, if you see that the new film of your favorite director leaves much to be desired, be honest to yourself and those who will read the review and admit it. And vice versa.
And the last tip, which is equally useful in any kind of writing: be yourself, don’t try to write as somebody who you are not. Employ the language and wording you usually use, refer to your experience – and you are very likely to write a lively, interesting review on almost anything.