How to look? By looking. A lot. At one point, Rancière puts it this way:
Emancipation starts from…the principle of equality. It begins when we dismiss the opposition between looking and acting, and understand that the distribution of the visible itself is part of the configuration of domination and subjection. It starts when we realize that looking also is an action which confirms or modifies that distribution, and that “interpreting the world” is already a means of transforming it, of reconfiguring it. The spectator is active, as the student or the scientist: he observes, he selects, compares, interprets. He ties up what he observes with many other things that he has observed on other stages, in other kinds of spaces. He makes his poem with the poem that is performed in front of him. She participates in the performance if she is able to tell her own story about the story which is in front of her. This also means if she is able to undo the performance, for instance to deny the corporeal energy that it is supposed to convey here in the present and transform it into a mere image, if she can link it with something that she has read in a book or dreamt about in a story, that she has lived or fancied.