Write a list of nouns. Then, use a dictionary to find the definitions, ensuring the word means what you think while jogging your mind with other possibilities. Instead of the proper definition, jot down nouns that could be used in comparison to the words on your list. For example, "airplane" could be called a "bird" or a "horse" to imply that it is a mode of transportation. A romance could be compared with a "dream" or a "nightmare."
Choose a solid topic for your poem such as romance, death or childhood. William Shakespeare wrote his timeless sonnets and plays with elaborate metaphors, often describing abstract subjects such as the meaning of life, time, and love. "All the world's a stage," Shakespeare wrote, comparing life to a performance in which people are mere actors.
Leaf through a dictionary or thesaurus to find ideas for metaphors. Select nouns rhyming with your lines of poetry or simply offering a pleasant or striking ring. Instead of "bird" or "horse," you could compare an airplane to a "gazelle" or "stallion." That "dream" or "nightmare" romance instead could be a "sunbath" or "downpour." Not all poems employ rhymes.
Starting with Line 1 of your poem, compare two nouns. Remember, do not use "like" or "as," because comparisons using those words are similes, not metaphors. "The airplane is like a bird," is a simile, while, "The airplane is a bird," is a metaphor.
As Shakespeare often did, continue the metaphor throughout Lines 2 and 3 of your poem. "This bird has barely learned to fly," can represent an airplane faltering in air, while "flying is sorrow" can describe the grief of a plane crash to a young husband's surviving wife and children.
Expand the metaphor for a few more lines. Consult a dictionary or thesaurus again to build upon the metaphor made in Line 1. Ask a friend or a fellow poet to read your work and make suggestions. Plan on rewriting a first-draft poem at least once if it is a school assignment. Every poem deserves a good editor.