1. Write down the ideas of your favorite teacher.

2. Write down your feelings about your favorite teacher.
3. Write down how do you feel about your favorite teacher.
4. Write down your idea about a teacher you like.
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Would you check thesentences? Which ones should I use?

2 and 3 are best. 1 could be to write down the teacher's ideas, not your impression of them. 4 is just rather clumsy and not quite clear.

#3 does not need the word "do". "Write down how you feel about your favorite teacher."