When choosing poetry for students, you should typically consider the nature and interests of the students to try to find poetry that might mean something to them. You should also choose poetry that is at the reading level of the students, unless you are purposefully trying to push them to read more complicated materials. If the students are just beginning to learn about poetry, then it is typically best to begin with simpler poems and straightforward messages, before moving on to more complex ideas. As you are choosing poetry for students, you should also be sure to choose poems that are thematically appropriate for their age range.
Choosing the best poetry for students does not have to be a difficult or complicated experience, but some care on your part can help the students be more open to the poetry you present. You should typically begin by considering what the interests of the students are, and trying to match those interests as well as you can. This can be difficult, of course, as students might not be interested in the same materials that many poets have drawn upon for inspiration. Given the wide range of poems that have been written over the years, however, you can likely find poetry for students with a variety of interests: from the military and athletics to nature and astronomy.
You should also be careful to try to choose poetry for students that is considered appropriate for their age. This means you should typically avoid poetry that goes into subjects that may be controversial, unless you are sure the students can handle such subject matter. There are a number of poems about subjects such as sex, death, suicide, drugs, and alcohol that may be poor choices for young students who are not ready to read about those subjects.
As you are considering poetry for students you should also look for poems that are at an appropriate reading level. You do not want to present students with a poem that is so complex and difficult that it will immediately turn them off of poetry without any attempt to understand what the poet expressed in the work. It is usually best to choose poetry for students of relatively short length, as such poems can be easier to read and understand. You should also look for poems that support or display any related subjects you may be covering with the students, such as voice, figurative language, rhyme, and other literary devices.