One trick used by behavioural scientists is to backchain the words - learn the last line first, then last two lines, last three lines, and so on back to the beginning, so you're always working towards strength.

Another is to use unusual images to fix the words in your head:

"Of all the comrades that e'er I had" (your best buddy with a Che beret with Communist star)
"They are sorry for my going away" (your buddy waving his beret as you sail off from the quay)