Here’s a useful tip for completing your listening and reading answers.
According to the the official IELTS handbook, Information for Candidates:
“You may write your answers in lower case or capitals” (Test Tips, page 6)
Writing in block capitals is a good idea here as it should be clearer for the examiner to read.
A curious thing is that you can also do the writing part of the exam ENTIRELY IN CAPITALS TOO! It’s not something I recommend but it’s interesting to know that it’s a possibility.