1.

With a final action that echoes outside the poem, a closure with sensual details that stick to the skull and stay in the room. I think of how Mary Ruefle ends "Lightly, Very Lightly" with this picture of a woman listening to the slow tick of a clock hidden inside a drawer, a mysterious count-down that is both intimate and unexplained:

somewhere the lady of the house
puts the alarm clock in a drawer
where she cannot hear it
then tells the children to be quiet
and stands there listening
to its tick.

2.

With an image that undermines a prior assertion or statement, thus casting doubt over everything you promised. Deborah Digges ends "The Wind Blows Through the Doors Of My Heart" with the invitation of "quiet, a quilt spread on soil", followed by the statement:

But we will never lie down again.

A poem that sets up this image of a peaceful quilt, a respite, and then denies access.

3.

With a statement that circles back around to the poem's first tentative breath while amplifying the pressure of that breath until you wince. The fingernails have been pressing into your palm the whole time and you didn't realize it. How could you have known Minne Bruce Pratt would leave you with:

The poem as the locked room.

(See "The Relation Between Words and People: After KR Rilke", American Poetry Review.)

4.

With a short question that is answered in a fashion that echolocutes its way through the poem. I'm thinking of complex, numinous way in Kayleb Rae Candrilli ends the lengthy, three-column poem titled “You've Heard This Before, The Only Way Out Is Through" with: 

there is a razor in the apple
and the apple is the earth. Listen,
my nightmares are dreams in which
everyone walks in the same direction--
that rhythmic lockstep. Both of my
grandmothers considered abortion.
And can you imagine?
Being so close to nothing?

5.

With an inclusive question that invites the reader in deeper, as in Aimee Nezhukumatahil's sonnet, "Naming the Heartbeats", which ends in this expansive “we “ that binds the reader's reverie to the speaker’s:

And what is the name for movement we make when
we wake, swiping hand or claw or wing across our face, like trying
to remember a path or a river we've only visited in our dreams?

6.

With a powerful image that reinforces or weaves together previous images in the poem. I’m thinking of the sonic boom that ends Wanda Coleman’s “Etheridge,” and how last line’s image—and the action in this image—feels like a speech-act or a sound-act or a space between the flesh and the portrait, and how sacredness inhabits this image by offering a subversive iconography that leans (loosely) on biblical lexicons:

he kissed the reefer burning his thief’s fingers
leaned against that bitcoin’ hood and blimped the itch

his blaze interrupted the sermon and singed and singed the robes

7.

With a pivot word (or words) whose re-definition that brackets the conflict in the poem by flipping it, fleshing-out the synonyms intimately. As in synonyms for what touches us become intimacy. I'm thinking of what Jericho Brown does at the end of "Hero" with black and dark, and how it refers back to gratitude. Starting with the sixth line of this poem because it what Brown does is incredible:

I am most interested in people who declare gratitude
For their childhood beatings. None of them took what my mother gave,
Waking us for school with sharp slaps to our bare thighs.
That side of the family is darker. I should be grateful. So I will be—
No one on earth knows how many abortions happened
Before a woman risked her freedom by giving that risk a name, 
By taking it to breast. I don’t know why I am alive now
That I still cannot impress the woman who whipped me 
Into being. I turned my mother into a grandmother. She thanks me 
By kissing my sons. Gratitude is black—
Black as a hero returning from war to a country that banked on his death.
Thank God. It can’t get much darker than that.

8.

Ending with an I statement that repositions the poem's direction. The poem plods along and then turns, ending in a strange action with repositions the narrator or the subject in an interesting way. It alters the light of the poem. I’m thinking of Gerald Stern’s “The Far Edge of Kilmer,” which ends with a statement:

I am holding open the burnt door.

Or Johanne Dubrow’s ending of a poem with “I hold this punctured story to the light.” Notice how the 'I' statements assert something about the future as related to the present, and engage the use of poetry itself. Often this sort of ending can have a metaphysical touch; there is a sense of mystery opened in action which makes the closing feel less like closure.

9.

With a question that affirms the value of uncertainty. Mary Oliver's poem, "How Would You Live Then?", is composed entirely of questions from start to finish. She ends on a question that underscores the sense of wonder in both tone and form:

What if you finally saw
that the sunflowers, turning toward the sun all day,
and every day--who knows how, but they do it--were
more precious, more meaningful than gold?

10.

With a prophetic statement, repeated for emphasis. The way Czeslaw Milosz ends his "A Song On the End of the World" (as translated by his son, Anthony Milosz) makes the repetition feel like a doubling, not quite a repetition so much as an enlargement of the space in which the first admonition operated:

There will be no other end of the world.
There will be no other end of the world.

11.

With an object that comes to mind after various verbal acts of refusal. In a poem about refusing. Practice saying NO at different pitches. In different places. With different props. Insist with Anne Boyer that you are "Not Writing". Or not missing. Or not overwatering the flowers in an urge to save the world. Develop a rich tapestry of no's that you can't resist. Aim for the most irresistible no you can manage, and give it texture, sonics, beat, passion, lyric. The most magic no. Learn from Anne Boyer's "No". But end with an evocative (and solid) object.

12.

In a liminal, haunted space that re-visions the skeletal. See: leaves disembodied by dusk. There are no bodies between shades of light, in the space inter day and night. And yet this space is less liminal than that of the cardboard flower hatbox on the top shelf of the closet. Ghosts. Every poet needs one to have the last word. Once. I feel like what I mean to suggest here is cryptic. And there is something very odd about quoting the crypt, so I won’t.

13.

With a couplet of doubled metaphors, especially if the lines enact a light parallelism by beginning with the same word or article. I’m think of Naomi Shihab Nye’s “Daily”, which ends so beautifully (I can’t even talk):

The days are nouns: touch them The hands are churches that worship the world

14.

With the title of a painting or an opera or a musical composition. Zach Savich does this in his prose poem, "Chestnut City", which ends the first stanza with a quote from Cocteau and then ends the second stanza--and the poem--with the title of a painting:

Could go to sleep in the bushes and wake and it will be like a fairy tale only nothing will 
change. "Path Before the Bride Appears."

15.

With a culmination, an escalating crescendo effect. See Deborah Digges' "To Science", in which the extended metaphor climbs, spirals, and culminates in a sort of evasive conclusion:

for nothing. Just thinking of your hands
I can go wet, or dreaming, come
in my sleep, and wake to a day
in which all men are liars, wearing clothes.

16.

 With an ending that explains or qualifies the title. This is a motion that swerves back around and returns to the beginning. It usually requires a title abstract enough to demand unpacking. For example, Heather McHugh's "Meantime" suggests a sort of time; it begins in the past tense to describe 'how things were', which it does for three stanzas before ending in a single-word, separated, set apart:

thirteen.

This word converses with "Meantime," and expands on the temporality (not to mention that it packs the power of a two-syllable last line, alone, revelatory.)

17.

Ending in exclamation or ecstasy. How Gerald Stern ends “The Dancing” with a sort of exhalation, a creative and spiritual breath related to the invocation of deity:

oh God of mercy, oh wild God.

The dissimilarity of the words wild and mercy do so much to heighten this effect.

18.

 With a precise, complicated simile. I love how L. Eric Greinke ends “SONNET XI. Even as the poem bends” (from his Sonnets for Ted Berrigan) with a precise and complicated simile:

Like your thighs upon the sheet.

19.

With a command or imperative, instructing the reader (or the You) to do something. I’m thinking of Sharon Olds in “I Go Back to May 1937,” where the final line shifts the stakes and alters the emotional valence into a sort of wistfulness:

I want to live. I   
take them up like the male and female   
paper dolls and bang them together   
at the hips, like chips of flint, as if to   
strike sparks from them, I say
Do what you are going to do, and I will tell you about it.

There is no closure because the next action depends on something external to the poem, namely, the You. I feel like Louise Gluck uses this strategy often, and it creates suspense or mystery which hinges on implication.

20.

With gorgeous alliteration and maybe ellipses. Even though ellipses seem to be on the wane, I know a few editors miss them. And some poets have made them magnificent; have used them in ways that change the breath at the end of the poem, or even change what we allow ourselves to have received from it. I’m thinking of how Gwendolyn Brooks ends “Jessie Mitchell’s Mother” with this sequence of slant end-rhymes and then the alliteration in the last line followed by ellipses:

Forced perfume into old petals, pulled up the droop,   
Refueled
Triumphant long-exhaled breaths.
Her exquisite yellow youth . . 

21.

With a last line composed of monosyllabic words that change the speed and motion of the poem by sharpening it. I’m thinking of Louise Bogan’s “Women,” which ends:

As like as not, when they take life over their door-sills
They should let it go by.