I am watching series called "Once Upon a Time" now.
To improve my listening skill in English, I watch every episode twice one without Arabic subtitle and one with it.
This way I do it before in another series called "Heroes".
This way force me to focus on sound which actors and actresses say in different situations and combine with different background sound like sound of a car and waterfall.
The ability to hear words with noise is very important.
Hearing old man is hard for me because he changes the pronunciation of words.
Now, I can understand about ninety percent of episode.
In generally, more practicing means more skill improved.