One of the fundamental rules of writing is to know the rules of spelling, grammar, syntax, etc. In the case of poetry, there are a few more rules, or at least structural options, such as rhythm and rhyme. It is important to know the rules and the options, and know when you are breaking the rules. Most writers and poets break rules at some point. The question is: "Are you breaking the rules consciously, or unconsciously?" Do you know why you are breaking the rule? Can you enunciate your reasoning in a logical fashion?

For example, it is generally considered proper in formal writing to write in the third person. This book is written mostly in the second person. Why is that? This is a self-help book directed at improving your poetry. If you read the title, you know this. It is not a scholarly monograph or treatise, it is a working guide for the working or aspiring poet. Hopefully, that means you! So the writing style in this book may not conform to the expectations of your 98-year-old Professor of Romantic Literature.

Peter Berryman, in a column for Sing Out! magazine, once suggested that the song "Mairsy Doats" works as a song because it breaks the rule that words should be understandable.

So what are some other reasons to break the formal rules? Expressing in dialect, giving the poem a period feel, creating an edginess to the poem, being an iconoclast like e e cummings, annoying people. These last two are not usually good ideas. There have been enough poetic iconoclasts, and it is doubtful that you can go further than your predecessors and get work published, sold, or enjoyed outside of a small circle of people. If this be your aim, charge ahead. In fact, following the rules may be a modern form of iconoclasm. As for annoying people, although it can be a fun hobby, in the long run it can be dangerous.