You may or may not know, but I recently added a poetry section to my website, where I posted several poems I've written in the past year. It's located here: http://www.ebblack.com/poetry.html
I've written poetry off and on my entire life. I think most people have done the same. It's because writing a poem is much quicker than writing a novel or even a short story. It's a faster way to get a feeling, thought, or experience off your chest.
That's not to say it's easy. Every word in a poem matters, so much more so than it does in a novel or short story. This is especially true if you want your poem to have rhyme and meter. While you can word your scenes a million different ways in short stories/novels and still have many of those ways be correct, it's not the same with poetry. There's only one right word at the end of each line. Only one word that makes sense in the beginning. Most of writing poetry is choosing a bunch of wrong words first, erasing them and replacing them with something better, until you find the right one. Every word in a poem changes the meaning, rhythm, and rhyme so much.
With a poem, you try to cram your big thoughts into a small space.
The mistake I think a lot of poets make is failing to communicate their message. When most of us think of poetry, we think of English class. We remember reading poems that were confusing and full of metaphors. We didn't get the poems or their meanings until our teachers pulled them apart by each line and explained them to us. So a lot of poets want their poems to be mysteries.
It's a pretentious sort of thing to want. You're mysterious so only "smart" people will get what you are trying to say. Then, later, when no one gets what you are trying to say, you feel frustrated and angry. You feel like your poem is too "deep" for anyone but you to understand.
Don't think I am attacking you if this is how you write poetry. That is how I used to write poetry as well a lot of my life. Also, there are exceptions to every rule.
But I don't think that's how poetry is supposed to be. Of course there are going to be metaphors and similes in poems, but don't become so abstract that no one gets you.
Writing is all about communication. It's the most important thing. Communication is more than just speaking words. You must say them in a way that people will understand.
Most people don't care about this, but it's a strong concern of mine because my mother has high-functioning autism. She speaks English, but sometimes it's like she's speaking a foreign language when she talks to other people. I get what she's saying because I've known her all my life, but most people don't. Watching her talk and forget to make eye contact or make weird hand gestures or say things at the wrong time gets her in all kinds of trouble, more than you would imagine. People get mad at her a lot when she has good intentions or ignore her when she's trying to speak to them.
If you don't know how to communicate in a way that people understand, they're not going to get what you have to say. Being confusing isn't going to make them like you more. My mother can't help that she's confusing, but a poet can.
What makes poetry great is not the clever metaphors and similes. It's the message. You want to say something that other people haven't thought of before or wish they could say, but don't know how. You want to convey the feeling behind the message, the darkness or the light, in your words. You want people to get it. It's more important for people to understand your message than to use metaphors or similes at all. Those are just tools, your message is what is actually important.
Look at the poetry people share on social media. I don't mean poetry they wrote themselves, but poetry other people wrote. It usually has a strong, emotional message that is conveyed very clearly. It's not usually ambiguous.
The point I'm trying to make is that when you write poetry each word is important, but don't get so caught up in the words that you forget your message.
I think this is the biggest mistake poets who are just starting out make.
If you'd like to read more articles on writing like this, please go to my site: The New Writer's Guide To Writing, Publishing, And More.