Pick a spot where you can write for a while without being disturbed. this could be a private spot where you are alone, or a public spot such as a coffee house or a park.
Begin by focusing on your immediate environment. Note the sights, sounds, smells all around you and start writing them down. As you do, let yourself get lost in your surroundings. You may want to to use apostrophe, or to shift perspectives.
After four or five minutes, turn your attention gradually inward to your experience of the scene--to what it reminds you of or how it makes you feel, for instance. Don't try to control or direct this process, just tap into your internal language. And keep writing.
Alliteration refers to the repetition of initial sounds of words, assonance to the repetition of vowel sounds within a word, consonance to the repetition of consonant sounds within a word, and rhyme to the repetition of both vowel and consonant sounds, especially, but not necessarily, at the end of a line.