Many teachers have used the Haiku style in classrooms, and I would say they teach it incorrectly.
Teachers will tell the class the Haiku style is a poetic structure that uses three lines. The first and last line have 5 syllables and the middle like has 7 syllables. Then, they try to get the students to write a haiku with this 5-7-5 structure without explaining why the structure exists. Lastly, students produce really bad poetry, and many of the students leave the lesson thinking that a haiku poem is easy, stupid, or have no respect for the concept.
A haiku shares emotion, and the 5-7-5 is not the hard-set rule, but the idea of the confinement of thought. Sharing one emotion or scene is very difficult, and it is made more difficult by forcing the structure of limited meter. English does not translate syllables the same way as other languages, and this structure is less about 5-7-5 and more about honing emotions.
I walk to the door I wait but you don't follow I continue on
This poem is simple, but in contains a powerful experience many people know and feel. Leaving a situation alone, when you expect someone to come with you. There can be sadness, stillness, and all types of depth of emotion. But each word may be simple, it is chosen carefully. Do not waste words!
So remember, when writing a Haiku style poem, make every syllable and every word count, but worry less about 5-7-5 than about brief imagery.
I will leave you with an example of non-5-7-5 haiku; notice how the spirit is there, but does not conform to the 5-7-5 pattern:
The breathing wind a crisp bite of the frost winter's woken
Remember, the point of the Haiku style is to share emotion and create controlled, powerful scenes. Write your own and share with others!
There is a worksheet of this activity you can download below: