Step One: How much do you know about the method of production?
One of the first things I think about when I write a critique is how much I know about how it was produced. For example, how much do you know about traditional art and the subsections? If the artwork is a piece of jewelry, I'm sure you wear it, but do you feel you know enough about the production of it to give the user an adequate critique on how to improve their work? What about digital painting or photo-manipulation? There are techniques that you might just not know enough about in order to critique a user on certain things. However, even though you may not be experienced, I still feel that you can offer ideas as a simple viewer, but you should stick to areas you do know about such as colour and conceptual things.
Step Two: Take a look at the thumbnail or small view and consider how well the artwork fits together as a whole? From this view, do any elements stand out or look odd in comparison to the rest of t