You just need to compare and contrast. If you wanted to do a Haiku and a Limerick you could say,
Haiku and limericks main difference is the structures. Haiku consists of 1 stanza, three lines that are 5-7-5. "Kochira muke. Ware mo sabishiki. Aki no kure." The first sentence consists of five words, the second seven, and the third five. Limericks consist of 5 lines with a rhyme structure of AABBA. There are usually nine words in the first, second, and fifth line and six to seven words in the third and fourth lines. The words can cut down to seven words on the first, second, fifth and four words on the third and the fourth lines. The form is called anapestic trimeter.  Despite the differences in structure, both of the poems must follow strict rules in the structure. Haiku poems must follow 5-7-5 structure and limericks must follow the anapestic structure. The words in the first sentence can't have more than 5 words, second line has to have 7, and the third has to have 5. All limericks must follow the anapestic trimeter pattern. Line first, second, and fifth must have three anapests. These three lines are longer than the third and fourth line. The third and fourth line must have two anapests.  Limericks rhyming would follow the AABBA pattern but Haiku doesn’t have any rhyming pattern. AABBA pattern is the first, second, and fifth line would have the same rhyming. The third and fourth line must have the same rhyming. “There was an Old Man with a gong, Who bumped at it all day long; But they called out, 'O law! You're a horrid old bore!' So they smashed that Old Man with a gong.” Gong, long, and gong rhyme with each other following the AABBA pattern. The last words of the third and fourth lines, which are law and bore also rhyme with each other. Since Haiku poems are usually short, they don’t have strict rules of rhyming pattern.
