The most important part of any English essay is the planning: you need to make sure that you know what you are writing about before you start. With a poetry comparison essay, you will usually be looking for similarities and differences in the poems. For a coursework essay, you can take your time over this, and the same skills can be used to do the same thing efficiently in an exam.
Step 1: READ!! Read the poems, and then read them again, and probably again just to be sure.
Step 2: After reading through both poems thoroughly, you can make notes for each poem according to STRIP factors: Structure, Tone, Rhythm/Rhyme, Imagery and Person. "Person" can refer to both the people reading the poem, and the 'speaker' or the voice telling the poem, so you could make notes on each one individually if relevant.
Step 3: The next step is to put all of these ideas into a plan, which compares the use of these STRIP factors. Usually GCSE questions are based on the themes, so you will be focusing on how the STRIP factors are used to create (or challenge!) the theme shared by the two poems. Comparing your notes, you are aiming to find a similarilty and a difference in the language - that is, imagery, tone, and person; as well as a similarity and a difference in structure - which includes the 'structure' part of STRIP as well as rhythm and rhyme.
Once all that planning is done and dusted, you can write the essay!
Part 1: Introduction: The introduction should be short and clearly explain which poems you will be writing about, and what it is in each poem that you will be discussing.
Part 2: Body: This is where all those similarities and differences go: it will depend on the poems, but usually it is best to alternate similarlity and difference. This will mean you have four paragraphs, which could go like this:
Part 3: Conclusion: After these four paragraphs, you can write your conclusion, which should be a few sentances long, and explicitly answer both the question and the introduction.
And you're done!
The settings of the two poems, like the characters, are totally different. In “The Indian to His Love,” Yeats makes no attempt to inject realism into his setting:
The island dreams under the dawn
And great boughs drop tranquility:
The peahens dance on a smooth lawn,
A parrot sways upon a tree,
Raging at his own image in the enameled sea.
Clearly, this is a nameless imaginary island surrounded by imaginary seas. Yeats' descriptions are in flowery metaphoric terms, and all combine to lend a dreamlike quality to the poem.
In “The Hosting of the Sidhe,” on the other hand, there are none of the qualities of setting present in “The Indian to His Love.” Yeats tells the reader exactly where in Ireland the action takes place: “The host is riding from Knockarea/ And over the grave of Clooth-na-Bare.” Yeats brings his poetry into the countryside of his people; and, even though his subjects are not real, except perhaps within the mind, they seem more rooted in reality than his hapless Indians.
Additionally, the depiction of action is different in the two poems. In “The Indian to his Love, “ Yeats makes no attempt to suggest action beyond the most static activity: “And wander ever with woven hands,/ Murmuring softly lip to lip.” Nothing moves; nothing betrays real life. There are no winds, no storms, and no passions on Yeats’ island, only “tranquility.” Yeats chooses every word carefully to reinforce this picture in the minds of the readers. He gives no glimpse of the changes he will make in later poems, including “The Hosting of the Sidhe.”
In “The Hosting of the Sidhe,” quite in contrast to “The Indian to His Love,” the entire poem suggests action: "The host is riding from Knocknarea" and "Our breasts are heaving, our eyes are agleam/ Our arms are weaving, our lips are apart." Here is a clear picture of Niamh on his fiery steed, rushing with purpose. Even nature is there in force: “The winds awaken, the leaves whirl round.” There is nothing within the poem that even remotely suggests peace and tranquility.