A few things to keep in mind while sitting down to write a poem:
1. Don't tell the readers what they already know about life.
2. Don't assume you're the only one in the world who suffers.
3. Some of the greatest poems in the language are sonnets and poems not many lines longer than that, so don't overwrite.
4. The use of images, similes and metaphors make poems concise. Close your eyes, and let you imagination tell you what to do.
5. Say the words you are writing aloud and let your ear decide what word comes next.
6. What you are writing down is a draft that will need additional tinkering, perhaps many months, and even years of tinkering.
7. Remember, a poem is a time machine you are constructing, a vehicle that will allow someone to travel in their own mind, so don't be surprised if it takes a while to get all its engine parts properly working.
- Charles Simic
Andrew: It isn't everything, but as the title says, 'a few things to keep in mind'. The main thing is to get down that first draft - then you have something to work on. Remember, all good writing is re-writing.