Poetry has a special language of its own. This is referred to as poetic devices or figures of speech, or figurative language. One way to help your reader understand your poem is through the use of comparison of objects. In poetry, the most common devices used for comparison are similes and metaphors.
A simile is a figure of speech in which one object is compared to another unlike object by using the words "like" or "as." An Example of this would be:"I wandered lonely as a cloud" ~ William Wordsworth
A metaphor draws a comparison without the use of "like" or "as" and states that one thing is another. An Example of this would be: "My love is a red rose" "Juliet is the sun." ~William Shakespeare
When using metaphors and similes, it is important to try to make them as original as possible. For example, comparing love to a rose is one of the most overused comparisons in poetry. If your comparisons and similes are fresh and original, your poetry will also be fresh and original.
Why not try and write a short poem using a metaphor or simile or both.