The following ideas were put together by the author as introductory advice for American college students who want to understand and write haiku.
A haiku describes an event or an occurrence that you observe. Therefore, when you write it up, a haiku becomes "a moment verbally taken out of time."
A haiku shows connection with nature. That is the reason why almost all haiku are directly related to a particular season. The Japanese recognize five seasons, which I divide into the four "natural seasons" (spring, summer, fall, winter) and one "cultural season" (New Year). In Japan, New Year is now celebrated according to the Gregorian calendar, but in older times, New Year marked the end of winter and the beginning of spring. In the occidental world, the events connected with Advent, Christmas, and New Year could be considered the equivalent of this cultural season, "new beginning."
A haiku consists of 17 syllables in the entire poem. It has no title or headline. (An introductory "headline" would have to be counted as part of these 17 syllables.) Traditionally, the first and third lines have five syllables each, while the second line has seven syllables. The Japanese definition of a syllable is somewhat different from ours, a fact which has led to some discussion about whether the Western haiku should follow "the 17 syllables rule." Some of this discussion is indeed interesting and worth pursuing, but for all practical purposes it is certainly not wrong, if not even advisable, to organize one's haiku in three lines with 5, 7, 5 syllables.
When writing haiku, don't fall into the trap of trying to give an event your personal interpretation. Describe the event as concisely as possible. Give the event its precise representation in language.
Always check whether you might have said something twice ("autumnal" + "turning leaves"; "Easter" + "first flowers", "harvesting [+] golden corn"). Of course, you can "harvest golden corn," but know 1. what you are doing, namely that you are using a trite expression, and 2. that the farmers, who are professionals and know what they are doing, "harvest corn."
Though words can be repeated within a haiku, no word in a successful haiku has the same meaning when it is repeated (Bashô: I am in Kyoto. / But when the cuckoo's crying, / I long for Kyoto [Ich bin in Kyoto. / Doch ruft der Kuckuck, sehne / ich mich nach Kyoto]).
Don't ostentatiously bring the "I" into a haiku. The real world, the world we share with all others is the material for haiku, not the esoteric, the exotic, the private and the personally unique. Good style in Japanese avoids drawing undue attention to oneself.
Good style in Western languages, however, might require the grammatical subject "I" (because leaving it out might suggest abruptness, but if that's not intended, the use of "I" is, of course, acceptable). Note that an undue "I" can slip into texts under many disguises, for example, when the writer personifies natural phenomena: "Trees turning their leaves, / speaking of their last beauty, ..." (the appearance of the trees tells the individual author something, but trees don't stand around talking about beauty), or with comparisons that only the author can make: "... trees turning leaves fast, as if / there were no time left," or adverbially: "...old trees bending mournfully / in the autumn wind."
Therefore, walk through the world not only with your eyes open, but with all your senses alert to the world's reality. Experience this reality to its fullest. The encouragement to put moments of this reality into words and thus give them some permanence, that's a gift of Japan to the world. (And the ability to see more of this reality than meets the mindlessly used eye is a gift of Western science that the good haiku writer is also thankful for!)
Realize the importance of haiku writing to the people of Japan. This part of their culture is certainly something that contributes to the mental stability of those who actively participate in haiku (as participation in religious ceremonies and cultural events such as concerts, theater, choir singing, reading, keeping a diary, etc., helps us maintain our mental stability). Japanese haiku life is something that by now has also exercised a tremendous appeal on us Westerners. It was only at the end of the last century that the Japanese culture opened itself to the world. Its visual arts (architecture, painting, print-making) and also its music were recognized almost immediately as something with universal appeal and inspired Western art (Impressionism, Madame Butterfly). The appreciation of their language arts, especially of poetry, had to wait a little longer. (Robert Frost once said in a private meeting: "Poetry is the most national of arts. You can't translate it.") But in the second half of this century, there is good access to Japanese literature, and attempts at writing haiku can be observed in many languages. Haiku, with their down-to-earth, extremely realistic approach to nature are actually very easy to comprehend.
If Westerners interested in poetry have difficulties with haiku, it is because our modern poetry actually requires us to tune in on certain s t y l e s of representing the world before we can get access to what is expressed (D. Krusche). The Japanese haiku is basically "objective"; the "I" is not intruding on nature as an outsider; it is a natural part of it. Authors and readers of haiku realize a moment in nature and in doing so are consciously or subconsciously "re-minded" of the relationship of this moment with the whole of nature.
Western haiku writers can and do learn a lot from the great Japanese authors. But high quality Western haiku will without doubt also be influenced by the traditions of great Western literature. Observing and appreciating the cultural contacts and exchanges going on in our time, I actually think it will not be too long before great Western haiku and Western haiku critique will also influence haiku and the understanding of haiku in Japan.