Make sure to get into a relaxed mood and atmosphere. Turn off your cell phone, shut the windows, put the kids to bed, whatever needs to be done. Then just think for a moment. Close your eyes and reflect on your day. Think about some of the emotions and feelings you encountered throughout the day. Frustration? Anger? Joy? Bliss? Think about anything in particular you may have noticed, something out of place or a random act of kindness.
Don't worry about rhyming. Poetry isn't just rhyming verse. While you are welcome to come up with a rhyme scheme in your verse, it isn't necessary. The poem constructed here will be in rhyming verse for those interested in trying that.
Set the tone or mood of the poem. Is it a sunny day? Is it raining? Snowing? Thunderstorms? Is it hot or cold? Sweltering or freezing? Try to think of adjectives to enhance your poem. Think of your poem as a short story. It should have a beginning, middle and an end. To start your first line, use a short description or feeling, as in "The wind blew harshly against her weathered face."
Move the poem (or story) along. If you're doing rhyme scheme, alternate the rhyming lines. Try to keep each line as long if not shorter than the previous one. "The wind blew harshly against her weathered face Rain fell from the sky, drenching her body Washing away her sins, without a trace."
Know that the three lines collectively are called stanzas. If you'd like to add more lines to your stanza, feel free to do so. Here's the first stanza: "The wind blew harshly against her weathered face Rain fell from the sky, drenching her body
Washing away her sins, without a trace."
Here's the second stanza: "Now she's left soaked and shivering in the night Without a soul around to warm her Or love and treat her right."
Continue on in that fashion until you feel the poem is complete or at a good stopping point. Many poems are short, only a few stanzas long, while others fill entire volumes.