How do I improve?
Obviously a publisher will look at a, "you left me! how could you!?" poem much differently than a 16 year old girl who just recently was dumped. The more you read and aggressively look patterns, the easier you can compose with something that will stand out from the bulk.
The most important thing is to read with a critical eye! It's the most obvious but many tend to stick to only writing. View famous and amateur works alike with a critical eye, and most of all, have patience.
Steps to Improve:
1. Read Classic Poetry
2. Read Poet Biographies
3. Read amateur poetry with a critical eye.
4. Subscribe to poetry magazines.
5. Read through the poetry exercises page.
6. Join a writing club.
7. Look for patterns and similarities of themes.
8. Look for different styles and apply them.
9. Define what makes your style different.
10. Read poetry criticism at your local library.