Write an original line of poetry in at least trimeter, containing consonance and assonance.

A line of poetry containing consonance and assonance in at least a trimeter  is:

They would dine with those they couldn’t stand!  

Explanation:  

A poem's meter is defined as the rhythmic structure in a line of verse, it's possible to look for a meter in all kinds of writing but poetry in particular often consciously  uses meter for some effect the process of representing a poem's meter using some  sort of marking system is called scansion.

Meter is the ratio of stressed syllables to unstressed  syllables in a line.

A foot of meter is simply a building block of meter that can be repeated any number of times to form a complete line of stressed and unstressed syllables.

They would dine with those they couldn’t stand!  

A stressed syllable is a syllable that drives the word forward whereas an unstressed syllable is just sort of along for the ride unstressed.  

In written English poetry we generally group syllables together as feet and classify them based  on the number of syllables in a foot and the order of the stressed and unstressed  syllables.

the correct order is:

you're your own worst enemy:

they're going to say what they say, but

their opinions aren't holding you

back. it's your self-defeatist

attitude that's keeping your work

from getting its due.

"the sandy walls seemed to collapse in on themselves"

and

"the bloodshot waters seemed to have no bottom"