It has long been a tradition for writing workshops to use one or more lines from a poem as inspiration for student writing. Selecting lines that are evocative give students a place to start. Teachers may or may not want to show students the poem from which the line comes.
Have students all write from the same prompt and compare the different interpretations and places they "go" with the same line/image. Both the divergent and the convergent ideas/images of student writing that results from a shared prompt can be a fertile place for discussion.
Read one poem together and then have students each select a line from that poem as the first line of a poem they write. Have students read their own poems in groups divided up by the use of the same line.
Have students each select a line (from one or a series of poems) as a prompt and write, then have other students take one line from a fellow student as the first line of their next free-write.
A teacher might consider a series of lines that are related on a theme or topic to use over the course of a unit as a daily start to class. This offers the opportunity to build deeper understanding of the topic as students continue to write and think and talk making connections from and to their own experience over the course of a few weeks.
One of the cardinal rules of writing workshop is that students do not explain or give a preamble before reading their own writing – a simple read around of a portion or all of what has been written can be done either with an entire class or in small groups.
A teacher may want to process with students after the read around – highlighting interesting points of similarity and/or of difference based on the prompt from the class as a whole. Or to ask for interpretation or evaluation of a line or a poem and its message. Teachers may ask students to reflect on their own successes or challenges in use of poetic devices or their satisfaction with the poems they have written. This stage of the writing process allows students to begin to think about changes they may want to make in their writing – but is a separate stage from the creative process initially.