There is one method which I have employed in teaching my children memory work, in particular, the memorization of poetry. It has proven itself reliable through all of my children. First you read the poem aloud to the child so he can feel the rhythm, the cadence of the poem. Make sure you begin with the title and author. They need to learn to quote both at the beginning of the poem. The student will learn it like the first two lines of the poem in this manner, and the title and author will be forever associated with the poem itself.
After reading through the poem once, you choose a small section of the poem to work on, depending upon the age of the student. You may want to try a couplet or a stanza. Then you read the line and have them repeat it. Follow this procedure for five minutes and then stop. Consistently practicing for five minutes a day will ensure your student learns the poem in no time at all.
This method works very well for any aspect of memorization. If the student is really struggling with some memory work (history dates come to mind) doing this memorization exercise at bedtime will help immensely.