There are some really useful comments and questions below the lessons on this site. Someone asked me: "What's your favourite type of comment from students?"
The answer is simple: my favourite comments are those that relate directly to the lesson above them. This tells me that the student has read the lesson and thought about it carefully.
Of course, you are welcome to ask other questions about IELTS, but comments that show an engagement with the lessons are my favourite.
Please note: I can't answer most comments individually these days, but I do still read them all, and they help me to create new lessons.