Ask yourself some questions. How do you feel right now? What do you want to say, express or show others? What feeling do you want to invoke? What kind of story do you want to tell? Asking yourself questions will guide you into the present moment and help you to focus. Feel free to write anything down that is present.
Continue writing. Write whatever comes to mind, even if it sounds absurd. The point is to find the jewels and phrases in your stream of consciousness. These will become your central focus. Write in any way you wish; don't worry about grammar or spelling. This is a draft.
Review your writing and see what pops out to you. If you know you want to write a poem about love, find the phrase or words in your writing that best describe your feeling. You want imagery. For example, you don't have to say, "This is a poem about love," but if you've written "red, full lips," that could be a good start. That phrase gives an image of sensuality.
Leave behind what doesn't work.
Take what you've gotten from your first draft and begin crafting your poem. Once you have an intention and a few simple phrases, you have built your framework. You might find that the words of your poem flow!