Make it where people want to grow up to be teachers. The only idea I have for changing that is to pay teachers A LOT of money. Not just decent money. I'm talking about medical doctor money or more. Make it where teachers are not only respected for what they do, but for how much money they make. Maybe doing so would cause more great-minded people to teach instead of being tempted to other things because of money or status.
Think of the people who have inspired you. Surely if you have had a great teacher, that person would be in your list!