Classroom decoration?

Okay. I am in student council and i am in charge of the decoration comittee where i have to decorate the classroom as a surprise for our advisor. I have no idea how to decorate it and i need a couple ideas....so far im thinking woman of steele cuz thats her last name is mrs steele and she love the woman of steele thing....so how should i decorate it? btw its a surprise because for teacher appreciation week nobody gave her anything cuz she planned it....any decoration ideas?