In brief, what you choose to feel and express shows in your poetry who you are. A second strategy for giving depth to such brief poems is to take advantage of the nature of the Japanese language itself. Many words used in Japanese poetry have multiple meanings and poetic resonances developed in a thousand-odd years of use. The poet who can take advantage of these characteristics can pack in a great deal of meaning in a short space.
Thirdly, haiku depends on the creative power of the reader, who must learn to bridge the gap between the images and the deeper meaning that lies behind them. A good haiku often juxtaposes two statements or images. The creative reader can learn to put them together. Remarkably, each image is often defined in terms of the other. Here, for example, is a famous poem of Bashō included in what is probably his most famous work, The Narrow Road to the Deep North (Oku no hosomichi).
iwa ni shimi-iru
The cries of the cicadas
semi no koe
Sink into the rocks.
(Translation by Donald Keene)
The reader is presented with two parts to the poem. The first is the word for "silence," or "stillness." The second is a sound: the cry of the cicadas. A sharp noise thus creates a sense of its opposite, absolute quietness. To make such a poem succeed, however, it is the reader who must connect the two. In that sense, reading haiku requires a highly developed level of intuition on the part of the reader. This kind of skill is quite different from the kind of intellectual knowledge need to read, say, the poetry of Wordsworth or T. S. Eliot. The feelings, that sense of unarticulated potential, are what give haiku its special vibrancy and life.
For many lovers of haiku, Bashō's The Narrow Road to the Deep North is his most moving and accomplished achievement. Never published during his lifetime, this travel journal has become on the true classics of Japanese literature, and, through a number of translations, is widely known and appreciated around the world. This poetic journal, which purports to be an account of Bashō's travels in the northern parts of Japan, was based on notes taken by the poet during his trip which he undertook in 1689, but they were heavily reworked over a number of years, so as to move the journey from a literal account of the facts to a whole new level of spiritual insight.
During the trip, Bashō was accompanied by one of his most gifted disciples, Kawai Sora (1649-1710). When Sora's own diary of the trip was discovered in 1943, the differences were immediately apparent. Sora carefully recounted the events of each day and explained one of Bashō's actual purposes in making trip, that of spreading the art of haiku into the hinterlands, and, of course, finding a way to support himself by serving as a teacher and an occasional judge for local poetry contests. Bashō's text, however, while not neglecting these aspects of his trip altogether, makes the trip a journey into the self, taking the opportunity to remove himself from his ordinary life in order to meditate on the higher realities of things, and even to attempt to reach a state of enlightenment by putting his art at the service of the Buddhist-influenced spiritual traditions of which he felt himself a part.