How to improve listening band score?
Listen to documentary, English dramas, news or radio programs.
One of my favorite radios is LBC. It is London based discussion in which there is a new presenter for every two hours with new topic. Presenter chooses topic and starts discussing it and then ask listening to give feedback, opinions and share their experiences.
Listen to selected program; make notes of points being discussed in the program. Keep writing them on your note book. Keep such practice for few weeks and feel a change. I guess, you would be able to use to identify people’s opinion, follow them and link details with main idea. That is what is assessed in listening module of IELTS exam especially in section 3 and 4.