This is a fascinating look at the writing of a poem and it isn't done in the way that we think of poems being written, but it may well provide you with some insight and a different way to go about your writing, at least some of the time.
Nothing is more clear than that every plot, worth the name, must be elaborated to its dénouement before anything be attempted with the pen. It is only with the dénouement constantly in view that we can give a plot its indispensable air of consequence, or causation, by making the incidents, and especially the tone at all points, tend to the development of the intention.And:
There is a radical error, I think, in the usual mode of constructing a story. Either history affords a thesis—or one is suggested by an incident of the day—or, at best, the author sets himself to work in the combination of striking events to form merely the basis of his narrative—designing, generally, to fill in with description, dialogue, or autorial comment, whatever crevices of fact, or action, may, from page to page, render themselves apparent.
I prefer commencing with the consideration of an effect. Keeping originality always in view—for he is false to himself who ventures to dispense with so obvious and so easily attainable a source of interest—I say to myself, in the first place, “Of the innumerable effects, or impressions, of which the heart, the intellect, or (more generally) the soul is susceptible, what one shall I, on the present occasion, select?” Having chosen a novel, first, and secondly a vivid effect, I consider whether it can be best wrought by incident or tone—whether by ordinary incidents and peculiar tone, or the converse, or by peculiarity both of incident and tone—afterward looking about me (or rather within) for such combinations of event, or tone, as shall best aid me in the construction of the effect.
For my own part, I have neither sympathy with the repugnance alluded to, nor, at any time, the least difficulty in recalling to mind the progressive steps of any of my compositions; and, since the interest of an analysis, or reconstruction, such as I have considered a desideratum, is quite independent of any real or fancied interest in the thing analyzed, it will not be regarded as a breach of decorum on my part to show the modus operandi by which some one of my own works was put together. I select “The Raven,” as the most generally known. It is my design to render it manifest that no one point in its composition is referable either to accident or intuition—that the work proceeded, step by step, to its completion with the precision and rigid consequence of a mathematical problem.And:
Holding in view these considerations, as well as that degree of excitement which I deemed not above the popular, while not below the critical, taste, I reached at once what I conceived the proper length for my intended poem—a length of about one hundred lines. It is, in fact, a hundred and eight.And:
I will leave it to you to read the rest of the essay, but I assure you it is quite fascinating to read of the rather mechanical way in which Poe composed "The Raven." And yet, it is very effective. Perhaps you will find some useful ideas here.
These points being settled, I next bethought me of the nature of my refrain. Since its application was to be repeatedly varied, it was clear that the refrain itself must be brief, for there would have been an insurmountable difficulty in frequent variations of application in any sentence of length. In proportion to the brevity of the sentence, would, of course, be the facility of the variation. This led me at once to a single word as the best refrain.
The question now arose as to the character of the word. Having made up my mind to a refrain, the division of the poem into stanzas was, of course, a corollary: the refrain forming the close to each stanza. That such a close, to have force, must be sonorous and susceptible of protracted emphasis, admitted no doubt: and these considerations inevitably led me to the long o as the most sonorous vowel, in connection with r as the most producible consonant.