Fair enough.
Well, in general I would recommend this for your essay.
For each poem (treat each separately, the point of this module isn't to make comparisons between texts), begin with an analysis using a reading or a critic's opinion. I'd usually use a reading I pretty much agree with, or same for a critic. That is pretty much the simple part. Hopefully your school has given you readings or critics so that all you have to do is learn the main points of this argument, and regurgitate it in the exam.
Then, you have to reflect on the poem, in one of a few ways. You could introduce another critic/reading and compare the 'validity' (or 'accuracy', 'bias', or any word you choose, really) of the different readings. OR, you could simply reflect on the one reading you've used in terms of your opinion, backing this naturally with textual reference.
Now, to the poems. 'Wild Swans at Coole' attracts generally two different kinds of readings, and you can use them quite easily. The first kind is Practical Criticism, and it comes from around the 1940's (use that fact if the question requires you to compare readings of Yeats OVER TIME). Practical Criticism only analyses a text in terms of the technical features of the language. So, any meaning found in the text has to be found IN the text. The context of the author (eg, Irish patriotism in Easter 1916 and Maud Gonne in Wild Swans) is completely irrelevant.
The other reading you could use for a comparison is Feminist. And it makes an awesome contrast, since a Feminist reading is concerned with what texts suggest about the relationship between men and women and representation of women within the text. So your Feminist reading will be almost ENTIRELY concerned with the meaning outside the text and the relationship between Yeats and Maud Gonne. Because these readings find two such different things from the same text, you can pretty clearly demonstrate the variety of readings of Yeats, and use that to discuss...well, whatever the question asks.
...Damn, long post.