Poet William Stafford says that just because someone can put together a sonnet, does not mean he is a poet. Do not constrict yourself to a certain form. If you're new to the poetry scene, consider writing in free verse and moving toward structured poetry. Free verse allows you to find your voice and does not limit your use of words. This allows you to figure out the kinds of sounds and rhythms you find most appealing. Once you have found your voice and style, you can venture to adapt a structure to you, not the other way around. Richard Hugo, author of "The Triggering Town," says that, "If a poet finds himself solving the problems of a form simply for the sake of challenge, he has the wrong form."
There are many who say they are unable to write good poetry on a computer, arguing it is impersonal. Hugo even goes so far as to suggest writing in only pencil, as writing in pen makes it seem like words can't be changed. One plus to writing by hand is that you can scratch out lines instead of deleting or erasing. This is helpful if you can't seem to get a line right; you can go back to earlier wording and combine it with new ideas. Often, your first instinct is the best. Another suggestion Hugo has is to use paper with colored lines, as it is easier on the eyes than black and white.
Killing your darlings is an expression writers of many genres embrace and despise. It means to cut out or get rid of your favorite part of the poem. Often times, writers find themselves ruining perfectly good pieces in order to fit in one good line. As good as that line may be, it may not belong in the poem. Sometimes if a poem is just not working, take out your favorite part, kill your darling. From there you can do two things: see what the poem is without the "great" part and construct another poem around the "great" part. Here, you may be able to create two fantastic poems, rather than abandon one because you can't make it work.
Be careful to not let your message trip you up. Hugo says you should, "Never want to say anything so strongly that you give up the option of finding something better." Sometimes writers begin writing one piece and end up with something completely different. Stafford says, "The action of writing...is the successive discovery of cumulative epiphanies in the self's encounter with the world." Put simply, writing should be an expression of yourself and how you view the world around you. If you write that, you can't go wrong.