To create a shape poem, choose a subject for your poem with an identifiable shape -- a tree, house, cat or cloud. Draw an outline of the shape lightly on a piece of paper; fit the words of the poem into the shape, or skip the outline and play with line breaks to create the shape of your subject as you write the poem. On a computer, use font sizes and line breaks to "shape" your poem into a picture.
Shape poems, sometimes called concrete poetry, are typically short and descriptive, evoking the subject in language as well as the visual form of the poem. Poets may be as inventive as their imaginations allow -- NASA's website shows an example of a poem about a plane taking off, using the positioning of the words to "draw" the plane's nose, fuselage, wings and tail as it taxis on the runway and begins its ascent.
In "Alice's Adventures in Wonderland," Lewis Carroll wrote a famous shape poem that looks like a long mouse's tail and ends in a tiny squiggle. "The Mouse's Tale" uses "tale" and "tail" as a visual pun. Popular shapes for poems are hearts, flowers, houses, circles and triangles. Animals, apples and trees are other choices.