Use a syllabic break. Simply put, this is letting the number of syllables per line determine where to place the break.
Listen to the sound of the poem. Read it out loud. Have someone else read it. Breaking the line in different places produces different tones. Try breaking the line where it would not normally be broken. This can create a sense of tension because the reader will be forced to pause slightly where they would not normally pause. This is called enjambment.
Let the words fall where they may, flowing into the next line naturally. Use no punctuation. The reader will be forced to read the poem all at once, with no pauses or breaks. This will create a sense of urgency.
Call attention to particular words by placing them at the end of a line. Determine the key words in your poem that hold all the feeling, the meaning of the poem. Place these key words at the end of each line to hammer home their importance.
Let your line breaks serve as punctuation. Many poets do not use punctuation at all. Instead, they let the line break indicate to the reader where to pause or stop completely. Walt Whitman did not add a period to the end of his poem "Song of Myself," thus leaving it to the reader to determine where the poem ended. Perhaps his intention was that the poem never ended at all, thus he used no period at the end.