As a parents of two kids 21 & 17 both who have had their challenges at school. The best teachers have been ones with a lot of experience & who have their own kids. My kids have had 1-2 gems over the years.

A good teacher:

Recognizes that all kids aren't alike, they learn at different paces, and with different styles. And they do their best to challenge every one of them.

Accepts that they can make mistakes.

Keeps on top of grading & returns assignments in a reasonable time.

Can effectively communicate with the students.

Knows the material well.

Enthusiastic and love the material they are teaching.