If you are at a private school or a school that uses uniforms (like I do) then you could go to your school administration and ask if you could have a Civi's or Dressdown day. The catch is any student who dress's down has to pay $1-$2. Our school has about 1500-2000 students, so in about 1 day we made $1500 :-p
It works VERY VERY well.
If you go to a non-uniform school then you could have a crazy hat day or something like that.
It works very well and you can have like 3-5 of them per year. We usually do this to pay off school dances or student government money
