Select a poetic meter for your couplets. Iambic pentameter is a common choice. Iambic pentameter lines contain ten syllables. These ten syllables are comprised of five iambs, or units consisting of an unstressed syllable followed by a stressed syllable. Literary critics refer to rhymed iambic pentameter couplets as heroic couplets. Examples of heroic couplets in English poetry include John Dryden's translation of the "Aeneid," Samuel Johnson's "London" and "The Vanity of Human Wishes," the works of Alexander Pope and John Keat's epic "Endymion." Iambic tetrameter, the meter of works like Andrew Marvell's "To His Coy Mistress" is another option.
Write the first line of your couplet. Pay attention to the last word of the line, as you will have to rhyme it later. Nouns are by far the most common choices for rhyme words. This is because it is easy to conclude your line with the end of a sentence or clause, the last word of which is often a noun. A very skillful author of couplets can often utilize a verb or other parts of speech, however, as in the following example from Alexander Pope's narrative poem "Eloisa to Abelard":
"How happy is the blameless vestal's lot,
The world forgetting, by the world forgot!"
Write the second line of your couplet. This last word of the couplet needs to rhyme with the last word of the previous line, but you must make this happen in an organic fashion. Read as many examples of couplet poetry as possible to find out how skillful poets have made their couplets sound effortless. See the first stanza of Book I of John Keat's "Endymion" for a famous example of beautifully flowing couplet verse:
"A thing of beauty is a joy for ever:
Its loveliness increases; it will never
Pass into nothingness; but still will keep
A bower quiet for us, and a sleep
Full of sweet dreams, and health, and quiet breathing.
Therefore, on every morrow, are we wreathing
A flowery band to bind us to the earth,
Spite of despondence, of the inhuman dearth
Of noble natures, of the gloomy days,
Of all the unhealthy and o'er-darkened ways
Made for our searching: yes, in spite of all,
Some shape of beauty moves away the pall
From our dark spirits. Such the sun, the moon,
Trees old and young, sprouting a shady boon
For simple sheep; and such are daffodils
With the green world they live in; and clear rills
That for themselves a cooling covert make
'Gainst the hot season; the mid forest brake,
Rich with a sprinkling of fair musk-rose blooms:
And such too is the grandeur of the dooms
We have imagined for the mighty dead;
All lovely tales that we have heard or read:
An endless fountain of immortal drink,
Pouring unto us from the heaven's brink."