The goal of memorizing scripture is not to be able to get the verses correct but to know it so well you can not get it wrong.  John Piper has written a great article about the benefits here. He quotes Dallas Williard and Chuck Swindoll among others.  

Several of us are memorizing Psalm 16. I think it is one of the most rewarding spiritual disciplines. It will bless you many times over.  A verse that has been hidden in your heart will surface just when you need it.  

It is hard work to memorize. Here are some tips from Brooke at Rivers of Water. She advises that each day you (1) review the previously memorized verses out loud 10x (2) read the new verse out loud 10x (3) recite the new verse 10x out loud.  Her post is linked here. She has a lot more to say and it is well worth your time. 

I think this will help me have a method to my memorizing. I would add (4) write it out from memory.  The physical act of writing the verses out helps to solidify it in my brain. 

I hope this helps!

Have a great day!