Art is a double-edged sword here. The poet focuses on "the art of losing," which she depicts as something wherein practice makes perfect. However, this isn’t necessarily an art we can ever truly master. The poem’s ironic command that we "lose something every day" (2.4) to practice getting over the sensation of loss implies that if we lose enough small things, we’ll be ready when we lose bigger or more important ones. No matter how practiced we become at the art of losing, though, we can never really be prepared for losses, which will always seem like "a disaster."
The other art involved in this poem is that of poetry. The entire poem functions as a kind of coping mechanism for the poet, who forces herself to confront her losses by writing them down. There is some power in this act of writing, as shown in her last line, in which the poet forces herself to admit that the loss of the beloved "may look (Write it!) like disaster" (6.19).