Free form is one of the most common types of poetry written by beginners, primarily because it doesn't require any real knowledge of poetic form. As the name suggests, there are no rules for rhyming or meter. A poet writing free form poetry simply writes words and lines of poetry in whatever way they come. This doesn't mean there is no form to the poem. Typically, after a free form poem has been finished and you read it, you will be able to see or hear a repeating pattern.
Inexperienced or beginning poets often think a poem has to rhyme. This isn't true. Poems can be rhymed or unrhymed. They can even have a partial rhyme scheme. There are no set rules. The choice to rhyme or not rhyme is one the poet will make during the construction of a poem. If a poet chooses to write a rhyming poem, he may choose to use end rhymes or internal rhyme. End rhyme is where words at the end of the lines of poetry rhyme, and internal rhyming is where words rhyme within a single line. A poet may choose to use eye rhymes (words that don't necessarily rhyme but appear to rhyme when you look at them as with "said" and "laid"). As a poet, you're free to choose your rhyme scheme.
Meter in poetry is the distinct rhythmical structure of the poem. It dictates how a poem is read by indicating where stressed and unstressed syllables fall. Even a free form poem tends to show a sense of meter when read. In poetry, each sequence of syllables is called a foot. Lines of poetry are made up of feet named after the structure of the syllable. Iambic pentameter, which is one of the most common poem structures in English poetry, consists of five feet of iambs. The iamb is a short syllable followed by a long syllable. There are five of these per line in iambic pentameter poetry.
Word choice and how the words are presented are as important to poetic form and technique as the metrical structure. Some poets write with a literal approach, but it is common for poets to rely on figures of speech to deliver a poem's message. Allusion, symbolism, irony, metaphor and paradox are all types of figurative language a poet might use when writing. A metaphor, for instance, is something described that actually means something else. If a poet describes a fire raging through a forest, devouring it, fire could be a metaphor for time and the forest our lives. Figures of speech can make writing and reading poetry more interesting because what's being said in a poem may need to be analyzed before it can be fully understood.