Get rid of the dots as soon as possible, even if you have to stumble through the tune a few times. The longer you keep using the dots, the longer it will take you to play it from memory. You might write down the first few notes in order to get started, but that's all.

Think about the tune at times you're not playing - hum or whistle it, or just let it play in your head. If you have a recording, listen to the tune over and over. It would even help to get the tune in your head by listening and humming or whistling it before you even start to play it.

Don't overpractice, stop when you get tired or it doesn't seem to be progressing. The last time you play it in practice, try and do it without any mistakes. Then it will be in your unconscious mind and the next day you will be amazed how much better it is.

Some tunes are easy, while others seem incredibly hard, so keep at it and don't get discouraged, eventually it will come.

Maintain a strict tempo at which you can easily play the tune without mistakes. After you can do that you can gradually bring it up to speed. It helps to tap your foot or use a metronome in order to keep a steady tempo. But first you have to get the tune down cold, and then play to your tapping foot, rather than tapping to keep up with your erratic speed.

Cheers, S. in Seattle