An abstraction is:
An idea, something intangible, something that you cannot experience through your senses
fear, pain, love, regret, happiness, sadness
Take a poem that you've written and incorporate into it a visual element. For instance, a poem about a city could incorporate the feeling of walking between tall buildings by writing a poem in columns.
Find an object with a surface you can write on, for example an envelope (like we did in class), a roll of tape, a cardboard box. Now write the poem that could only be written on that surface, in other words, the physical form of the poem should contribute in an essential way to the meaning of the poem.
Use a form that is not a literary or poetic one and write a poem in that genre. You could write your own index, like "Love, and Index," a menu-poem, a receipt poem, a table of contents poem, etc.