The enotes link below is really quite helpful. It actually goes through the steps on how to "approach" a poem. It is a great starting point and I think offers many good insights on how to address the issue of poetry explication. I would check here and examine these tips. From my own experience, I think that poetry understanding, like poetry itself, is a very subjective experience. It is going to be up to the individual as to how to approach a poem. When I teach poetry, I ask students to try their best to take the poem in phases. The first would consist of understanding the surface meaning. Grasping this, in terms of fully being able to understand the literal meaning of what is happening in the poem would be a good starting point. From this, an exploration of the images, mental pictures used, would be another helpful point of reference. Examining how the poet is able to paint their picture through these pictures would be very helpful. Finally, I think that sensing if there is a symbolic meaning present would be the step where the most amount of discussion is present. This is where things get very dicey and often get the most challenging, but in taking things in phases and parts might also be the point where the greatest reward lies.