Examine the past

Look into the crystal ball of your past to see where you might have gone wrong (or perhaps went right). What clues do you find there? If you made mistakes in language-learning, you don't want to repeat them if you decide to make a new attempt.

If you ever tried to learn another language and quit, why was that? What did you hate at the time? What put you off? What did you lack? Was your approach (or that of your teacher) wrong? In what way? Was the timing wrong, the setting, or your expectations?

Figure it out as best as you can. Then institute changes. You wouldn't want to repeat the same mistakes.

And if everything was wrong, then do everything the opposite! 

What can that hurt? You couldn't do any worse.

Try different things, and don't stop until you latch onto the correct formula.

Think of Edison and all of those light bulbs that he went through!