Decide on a theme. This is an important step to take before you start to write a picture poem, because you need to pick an idea that inspires both visual and literary images.
Decide on the basic visual shape that your poem will take. For example, a love poem could be written in the shape of a heart (but your poem will probably be better if you choose something more unique).
Start the brainstorming process for your poem. Concentrate less on the final form of the poem and more on the ideas you want to express, and any particularly pleasing words or phrases that come to mind.
Sketch the form you chose roughly on scrap paper.
Use a pencil to start writing your actual poem within this shape, using the words and concepts you brainstormed earlier. Actually writing inside the shape will help you keep track of how short or long the final poem needs to be, and whether there will be any line breaks based on the visual form.
Keep in mind that you can modify your shape if necessary. For example, if you really want to write a longer poem than you can fit in your shape, make another sample with a slightly larger shape.
Edit the poem and shape until you're completely satisfied with both.
Draw the image in pencil on your good paper.
Fill in the poem in pencil, using the actual style of handwriting you prefer for the finished version.
Go over the words with pen, and also the outline if you want to keep it in your finished picture poem.
Wait for the ink to dry thoroughly, then go over the paper with eraser, cleaning up any extra pencil lines or smudges.