Well it would seem you have forfeited the round for an unknown reason. I will present my arguments.
Because you are con and your title states "Against School Uniforms" that would mean you are against, not having school uniforms. Meaning you are for school uniforms. I am not sure if you purposely did this, but for future reference, remember that Pro means you agree with the title of the debate and Con means you disagree with the title of the debate.
We should not have school uniforms for the following reasons:
1. "Uniforms violate the student's freedom of speech and expression."
You are restricting the student's way of expressing themselves which can keep them from sharing themselves and who they are with other people.
2. "Cost too much for families who already struggle to make ends meet."
This is a problem for families who would otherwise have their children wear clothes that are cheaper than the school uniform itself. Sometimes every dollar counts for families who already struggle to keep their children in school.
3."Emphasize conformity, not individuality, and do not allow students to develop their identity."
Not everyone is the same, nor does everyone want to be. People want to be their own person! Uniforms restrict students showing their own individuality.
4."Hide warning signs that point to problems. Often the way a child dresses can indicate the way he is feeling. Uniforms eliminate these red flags."
This is self-explanatory.
5. "Fail to allow students to learn to make good choices based on their own values."
Children need to make their own choices and learn from their mistakes. Giving everyone a uniform does not teach them what is appropriate to wear in circumstances and what is not. Children need to learn themselves what is appropriate and what is not. Giving them the right to wear their own clothes will allow them to test these boundaries and see what works and what doesn't.