End with call to action or pronouncement.
But you can write in any form that you like depending on the occasion, subject, and your skills. It is an easy way to attach concrete images to feelings and character traits that might usually be described with abstract words.
Write down whatever comes to your mind when you think about the person you love. For imagery, the poet may choose to compare himself and his partner to the sun and the moon — a classic but nonetheless lovely image that has been used by poets for centuries. You dick!
In your poem, compare how your life was before and after this person began playing a role in your life story. What do you like about this person? Where were you? It is hard enough to compose a poem without dealing with the intricacies of rhyme and meter.
Flowery language may look good on paper, but it may not express everything that you feel. Or were your gradual meetings resulted in the love? People use italics too much in poems to mean This is really, really deep.
This is so breathlessly important.
Consider reading about different forms of poetry to understand which will be better for your poem.