I use good technique that helped me greatly improve my listening skill.

Find video lesson in your target language with subtitles. Language teachers have good pronounciation, so, recognizing words takes less effort. you can find many ones on youtude. at the begining switch subtitles off, listen to about 10 second, next, If you can't recognize any words rewind video at the beginning of this 10 second segment. listen to this segmen again one or two times. still can't recognize what you heard? switch subtitles on and listen to it agan. there is two cases why you can't recognize those words. first - you are really don't know certain word, and second - you know the word, but you have wrong pronounciation of this word. fix it and move forward to the next 10 second length.

You'll see how you level up your listening skill in about a couple of months