There are many methods to learning lines:
- Singing them
- Drawing them
- Listening to them
- Rehearsing with someone
- Rehearsing with an application
Any method that requires you to have to recall the lines form memory is where they really start to stick in your head. So Rehearsing, or any method where you recall the lines without the script will make you learn better, only check the lines if you are struggling to remember, and then get back to it.
If you struggle with one method try another, or combo of methods.