Greetings Calmador.
It is good to see you entering into the realm of writing poems. I think this world could use more poetry (especially from a Christian perspective).
Personal advice I would give you as you begin in poetry would be the following:
1. Although there are differing views on the subject of whether or not poems need to rhyme (as is already seen in this thread), I personally do not believe poems must rhyme. Although my poems do in fact rhyme, I do that more out of a personal preference rather than following a rule. Some people have many great thoughts and ideas to share, but cannot necessarily write out their thoughts in the form of rhyme. So it would be a tragedy for those people to keep their thoughts to themselves and not write at all simply because they are told their poems must rhyme. Rhyme or not, write away.
2. Length of poems. As I personally don't believe poems have to rhyme, I also don't believe they have to have a certain amount of words or length of lines. My poems are on average about 32 lines long (one of my poems is 65 lines long) and yet one of my all time favorite poems to read is by Skylar Harris and is only 4 lines long, as seen below,
Birth does not exist alone
It dwells with death and loss
As in the humble manger looms
The shadow of the Cross
- Skylar Harris
I think it actually takes more skill to express a lot in a short poem than it does to express a lot in a long poem. So again, I would say don't be concerned about the length of your poems, as long as you are expressing truths in a clear and meaningful way.
3. Don't "force" poems. What I mean is that I never sit down to write a poem until I feel very strongly moved and inspired to write (which usually happens as I am reading a particular Bible verse or chapter during my personal Bible study time). That is why I personally only write about 2 or 3 poems a year. I would never say to myself "Hey, I haven't written a poem in 6 months, so I better sit down and write one immediately". To me that would just be forcing out a poem for numerical reasons and have no inspiration behind it to drive it on. So I would say wait to be moved and inspired before writing a poem.
4. Prayer. This piece of advice connects with my third point. After I've felt inspired to write a poem from reading Scripture, the very first thing I do before writing even one word is to pray and ask the Holy Spirit to guide me through each line and not let the poem be merely a product of my own strength and effort. We should not only write poems "for" God but "with" God.
5. Poetry for God's glory. Ultimately our poems are to bring glory to God, not to ourselves. When I read poetry in the Bible (which is the entire book of Psalms), I never once say to myself "Wow, what great poets King David and the other Psalmists are!" Instead when reading the Psalms my mind and heart are captured and focused on God Himself, not on the writers of the Psalms. So it should be with our poems; let God be the focus and purpose of your poetry, not yourself.
I hope these points can be of some assistance to you Calmador.
May God bless your newly found gift of poetry for His glory.
"May the words of my mouth and the meditations of my heart be acceptable in thy sight, O Lord."
- Psalm 19:14