I want you to use a wide range of resources and listen to a wide range of accents as well.You are going to meet people from all over the world with all different accents and you're going to need to understand them.So you need to be able to recognize more or less everything and diversify your English.Focusing on that word 'variety' again.
How much time do you actually dedicate to practicing and improving your listening skills? Most of the students that I asked say around 1 to 2 hours and even then they might be exaggerating a little bit. Now you've recognized that: You're probably not practicing enough.I want you to start practicing. Honestly, practice makes perfect! You're not going to suddenly wake up and be perfect at listening. It takes time, it takes dedication and it's called a skill for a reason.
Well, I've got lots of recommendations for you which brings me to my next point: “Resources and more importantly variety of resources” Now the most obvious one is watching TV programs or movies in English. That's good, but you don't want to rely on the subtitles. I want you to learn with your ears and not with your eyes. So what I recommend you do to take your listening to the next level is “Watch each program or movie TWICE!” I recommend that you aim for something that's less than 30 minutes. So, I want you to watch it first with no subtitles, see how much you can understand，and then I want you to watch it again with subtitles, and see what you did pick up and what you didn't pick up and then note it for next time. Don't be afraid to replay things again and again and again!
Learn the patterns of voice that we use. If you've got a listening exam or you're going to have a telephone conversation or some sort of interview over the phone, you're not going to be able to read the person's lips which can be really useful. So, you really ought to practice listening blindly!