In his bleakness and irony, Phillip Larkin's tone reflects the search for meaning in a disillusioned twentieth century. And, yet he is not as dark as Thomas Hardy, whom he admired and imitated to some degree with his colloquial, self-mocking tones, because he is more amused by ineptitude, and friendlier toward his readers. Indeed, he sympathizes with the dreamer, for whom the modern world is alien and suggests a stoicism and lack of self-pity which will maintain one's integrity.
In order to compose an essay about your personal response to the poety of Larkin, you may, therefore, wish to select poems that reflect similar tones to which you personally relate. If, for example, it is the irony of Larkin that you enjoy and react to, then you may wish to choose poems which evince this ironic tone. Or, if it is Larkin's sympathetic tone that touches you, find poems which demonstrate this mood. This tone, then, can become part of your thesis. For instance, you could make a statement about how this tone touches you and helps you understand your own discontent, or whatever emotion you feel.
One poem that exemplifies Phillip Larkin's overtone of sardonic humor that accompanies his underlying tone of chagrin, is "Toads." In this verse, Larkin creates a conceit that mimics such classics as "Rape of the Lock" by Alexander Pope, the eighteenth century satirist. Humorously using a pun with the toad, Larkin wishes that he could make the "leap" to exist as others who shout "Stuff your pension!" and free themselves of the drudgery of a job that they hate. But, he is not "courageous enough" because
...something sufficiently toad-like
Squats in me, too;
Its hunkers are heavy as hard luck....
and prevents him from acting on his condition. Like "Toads," many of Larkin's poems are variations on a self-deprecating theme that is usually presented with wry wit. Often, it is this witty tone that helps to alleviate the melancholy of the poet's lines that many respond to positively while at the same time they do relate to his rather morose subject matter.