In IELTS Listening exam, when you have to complete sentences, make sure that the word or phrase you write is correct both in terms of meaning and in terms of its grammar.
If it doesn't fit grammatically, it's the wrong answer.
It is easy to forget the meaning of new words. Try to work with new words you come across: look at the different related meanings, look up the different word forms and use them in a sentence about yourself.
The more you do with a word when you first come across it, the more likely you are to remember its meaning later.
In Writing Task 2, if the question asks you to “discuss both views” then you need a balanced argument, so make a list of ideas for and against the issue, and then give your opinion (I believe; I think).
Note that Task 2 counts for twice the marks of Task 1 so spend twice the amount of time on it. It is important to write at least 150 words for Task 1 and 250 words for Task 2.
In IELTS Speaking exam, when you have to answer questions in Part 1, don't just give one-word answers. You have to show that you can communicate in English. Try to say several sentences for each answer.