As someone who has experienced both a school time with...
School uniform
As someone who has experienced both a school time with and without uniform, I think they are something most schools should have. A school uniforms removes the ability to judge a student on his or her clothes. And the need for parents to spend money on brand clothing, just so their kids can fit in. It forces the student to be creative and express themselves in their work rather than with provocative clothing. It would also cut time in the morning. Instead of choosing clothes you would always know what to wear. Many great minds uses the same clothes to remove the decision making process in the morning so they can come up with greater things during the day.