Select the person that will be the subject of your monologue poem. It can be about you, a friend, a historical figure or a fictional character of your creation. At the beginning, it will be easier to write about someone or something you know, and as you get comfortable with the style of monologue poetry, you can play with creating your own character and scenario.
Write down a description of your character. This exercise will help you understand how this person ticks, even though you won't end up using all the information. As you flesh out a character in your mind, he becomes more lifelike, and you will get to know how he thinks and feels about various situations. Map out the time line of her life, her physical appearance, her attitudes and her defining traits.
Choose a specific event about which to write. It will be easier to flesh out your character's internal workings if you don't tackle a broad subject. For example, instead of focusing on your character's entire life, pick one episode in his life, such as a car accident. You can also write several poems about several significant events to create a short poetry collection.
Write your poem using the targeted event and the character description you wrote. Be as honest as possible. Most people are not entirely good or entirely evil, and the more conflicted your character, the more realistic she will be.