In IELTS Speaking, you have very little time to impress the IELTS examiner so you need to try and use less common/idiomatic language. Often it is language that is too informal for IELTS Writing, but excellent for IELTS Speaking.
A stronger version of bored to tears is bored to death.
I'm not a massive fan of Shakespeare. I had to study it at school and I was bored to death.
The last book I read was for my economics course, I can't remember the name, but I do remember I was bored to tears.
I'm not really into romantic comedies, the one I watched with my girlfriend and I was bored to death.