It's often tricky memorizing which memory verse goes with which part of the Bible. If you find yourself staring at Psalm 119:11 thinking "I know this verse, I just can't remember which verse in which Psalm it is" then you should start making up a story that goes with each verse reference. For instance, when I see Psalm 119:11 I immediately think that the 9 is hidden in all the 1's and that jogs my memory that the verse is about hiding something somewhere.
The more ridiculous the story is, the easier it is to create the association in your head. You'll find that as you start to have more memory verses, it gets harder to keep track of which verse connects with which reference. Creating an association in your head becomes key.
I'd love to hear some of the associations that people have created. If you use this method for memorizing references, why don't you post your most memorable one in the comments. If you have a different method of memorizing the references, share that with us all too.