well, the key thing is not to listen for a complete understanding of a context but for noting down answers quickly on your answer sheet.
Tips:
1. During exam, only concentrate on your question paper and answer sheet. Don't look around at all even for a second.
2. A first recording will be played for a volume check, use this 30 second period for looking at your questions and underline key words around fill ups. In real listening, synonyms/rewording will be used. so you can locate answers easily and quickly. have a great deal of practice at home following these strategies until they become a second nature. Also, predict answers in your mind, if there is a number , address, name given on your answer sheet..so you will exactly know what kind of answer/info there will be for your questions.
3. Write down your answers quickly. So practice a lot with a pencil. Nowadays we are used to typing so we are quite slow with writing things down manually.
4. Check back your answers thoroughly , why you have made a mistake etc, there are actual transcripts given at the back of each cambridge book.
Listening:
1. Listen to BBC channel or radio. Mostly British accents will be heard during an actual exam, so acclimatize with the British accents.
2. While listening to a recording, write down key words/info on your paper. Do this practice for 30 minutes.
3. Practice a lot at home. Do at least 10-12 tests if you are a weak listener. And, you are good to go.
Ielts is more like a game than an actual test of assessing language skills. I mean, even if you hear and understand the answer but too slow to write your answer, you are going to miss the answer and for other other questions as well. Same for reading, you need to locate answers under timed conditions it does not matter how good a reader you are in real life.