Arts criticism isn't just the domain of academics or art historians-there's plenty of room for non-expert but informed responses to the arts. However, critical writing still requires the rhetorical skills of a confident writer and the passion of someone well-versed in the area on which they're offering opinion. It's all too easy to do lazy, ill-informed arts criticism-but the best of this kind of piece can provide works of art and performance a sort of immortality in the human conversation, even if the critic offers a mixed assessment. Critical writing can provide some much-needed historical and cultural context within which to evaluate and talk about all kinds of artwork. When done well, reviews and criticism also serve to open a dialogue between the public and artistic work. After all, artists are rarely doing work merely for themselves-they're intending their offerings to be publicly available. The critic can provide a proxy voice for that arts audience-as well as serving to provide some unvarnished feedback to the artist about how their work is received. Offering fair-minded, honest critique is a valuable service to both the arts community and the art-consuming public, but it requires intellectual courage, rhetorical rigor, and strength of conviction.
Write on what you know: Only tackle arts criticism in an area of the arts where you're confident in your knowledge of the field and cultural context. If you don't have the confidence of passionate interest and some background knowledge, your writing will lack strength of conviction when you're offering your honest opinion.
Be fair and give evidence supporting your critique: Approach artwork critically, but be judicious and fair-minded in your critique, offering rhetorical evidence for your assessment (good or bad)
Offer an assessment of the work at hand, not the artist or the artist's history: confine your criticism to the work at hand, and try not to be swayed by an artist's earlier work or personal history.
Resist the urge to offer sweeping judgments: make sure you mean everything you write. It's easy to overstate your point. A simple way to check yourself is simply to read over every main argument you make and ask yourself, simply: "Is this really true?
And once again, don't write about people you know. It goes without saying, but it's almost impossible to offer dispassionate, fair-minded critique of work by those with whom you have a pre-existing personal relationship (friends, colleagues, exes, or anyone with whom you have, or have had a close acquaintanceship-whether the ties that bind you are affectionate or adversarial). There's virtually no editor that will knowingly assign such incestuous criticism, and it's a mess to untangle when it goes wrong and close ties are revealed after-the-fact.