Ten lines of iambic pentameter or Shakespeare in the morning

In June I heard a writing prompt from poet Ellen Bass: start the day with ten lines of iambic pentameter. You know, the meter of Shakespeare's sonnets (fourteen-line poems following a rhyme scheme and ending with a rhyming couplet) and most of the lines in his plays (blank verse generally without rhyme).

da-Da da-Da da-Da da-Da da-Da
da-Da da-Da da-Da da-Da da-Da

English doesn't always divide neatly into pairs of unstressed and stressed syllables, however. A famous example might be

To BE or NOT to BE that IS the QUESTion
WHEther 'tis NOBler IN the MIND to SUFfer
The SLINGS and ARrows OF outRAGeous FORTune
Or to TAKE ARMS aGAINST a SEA of TROUBles,
And BY opPOSing END them? To DIE, to SLEEP—

The first four lines of Hamlet's soliloquy end with unaccented syllables that exceed the official iamb pattern (short long). Only in line five, on the word "sleep," does metric clarity briefly emerge. I see a trochee (long short) in "WHEther," reversing the stress pattern, and an anapest (short short long) in "Or to TAKE ARMS," giving the passage additional variance that is common to the form. Wikipedia has helpful entries on metrical feet and prosody. I'm somewhere near the beginning of my understanding.

Looking at Shakespeare's sonnets, I'm sometimes unsure where the five stressed beats fall. The same thing happens when I write in iambic pentameter, a task that may be more difficult in modern English than in Shakespeare's time. For example, he makes use of a spoken difference between "rhym'd" and "rhymed" and of truncated words like "wher'er" to tailor the text.

Here are some sonnets that caught my eye today. The final example (CXXIX) was my favorite back in high school English class.

                         XCVIII.

From you I have been absent in the spring,
When proud-pied April, dress'd in all his trim,
Hath put a spirit of youth in everything,
That heavy Saturn laugh'd and leap'd with him.
Yet nor the lays of birds, nor the sweet smell
Of different flowers in odour and in hue,
could make me any summer's story tell,
Or from their proud lap pluck them where they grew:
Nor did I wonder at the lilies white,
Nor praise the deep vermillion in the rose;
They were but sweet, but figures of delight,
Drawn after you, you pattern of all those.
     Yet seem'd it winter still, and you, away,
     As with your shadow I with these did play:

                           XCIX.
The forward violet thus did I chide;--
Sweet thief, whence didst thou steal thy sweet that smells,
If not from my love's breath? The purple pride
Which on thy soft cheek for complexion dwells,
The lily I condemned for thy hand,
The roses fearfully on thorns did stand,
One blushing shame, another white despair;
A third, nor red nor white, had stolen of both.
And to his fobbery had annexe'd thy breath;
But for his theft, in pride of all his growth
A vengeful canker eat him up to death.
     More flowers I noted, yet I none could see,
     But sweet of colour it had stolen from thee.

                          CXVI.
Let me not to the marriage of true minds
Admit impediments. Love is not love
Which alters when it alteration finds,
Or bends with the remover to remove:
O no; it is an ever-fixed mark,
That looks on tempests, and is never shaken;
It is the star to every wandering bark,
Whose worth's unknown, although his height be taken.
Love's not Time's fool, though rosy lips and cheeks
Within his bending sickle's compass come;
Love alters not with his brief hours and weeks,
But bears it out even to the edge of doom.
     If this be error, and upon me prov'd,
     I never writ, nor no man ever lov'd.

                         CXXIX.
The expense of spirit in a waste of shame
Is lust in action; and till action, lust
Is perjur'd, murderous, bloody, full of blame,
Savage, extreme, rude, cruel, not to trust;
Enjoy'd no sooner, but despised straight;
Past reason hunted; and no sooner had,
Past reason hated, as a swallow'd bait,
On purpose laid to make the taker mad;
Mad in pursuit, and in possession so;
Had, having, and in quest to have, extreme;
A bliss in proof,--and prov'd, a very woe;
Before, a joy propos'd; behind, a dream;
     All this the world well knows, yet none knows well
     To shun the heaven that leads men to this hell. 

And what's a prose writer like me to do with this prompt to write in iambic pentameter? In July I shared one "10-lines" exercise that became a pumpkin sonnet. Any good exercise gets writing and observing and thinking motors to move--a lot like practicing an instrument or looking at paintings. Perhaps "10-lines" is an hour of yoga. Summer vacation turned out to be a low writing time for me--with my focus more on family time, travel and visitors. I got some translation work done and read a bit, but my writing gears cranked minimally.  Yesterday, taking a break from the lesson plan I need to write, I pulled the exercise out again, scooted my chair over to the window, put my journal in my lap, and forged lines. Nothing came easily, but I urged myself line-by-line to come up with ten lines. It worked. I wrote eleven lines. Technically I was writing from memory, but looking out the window at the deck helped me recreate a brief sighting from the day before. The rhyming "happened," and I didn't like it better when I pushed for more rhymes, so I left the text the way it emerged. As ever, I marvel at the possibility in words. Poetry demands awareness on about a million levels. I'm thrilled when I can get a few levels going.

A stately swirl of beige with mauve and brown
adorns a shining carriage, light and round
as a ping-pong ball that’s poised an inch above
the rain-filled rills, appearing not to move
out there across the soggy wooden plank.
Sunlessly pale a narrow tail lies still.
What sign, then, of motion, purpose, life?
Slug-snail, are you crossing such a vast
expanse to reach my garden, munch my plants?
Two rubbery antenna pairs turn right
turn left, turn right, point straight: the creature’s pace.