....uhhh....ummmm... oops...was the only thing I came up with asked by my team lead, I need your B.O.Y. folder. Oops I had no idea that by the E.O.Y. "end of year" there were certain things I was supposed to have been saving in a special folder all year long.
So do yourself a huge favor and start a file labeled BOY and every couple of weeks put some work samples from different subjects for each student. When the winter holidays come around start a middle of the year folder too. On the first day of school I would ask the kids to draw a picture of themselves, I would save that and have them repeat the assignment near the last day and give them the original to see the difference.
You could even save simple little writing assignments like this one. I have my students keep a writing journal everyday so I also have those samples that I could pull from as well.