S.F.
My son was (and still is) very involved w/ theatre.
Some families did flowers, even for boys.
We do little things that he enjoys... a book, a t shirt, candy, etc.
A gift bag could hold anything, and a balloon tied to it is another great idea!
We also save tickets and programs to add to a memory book.
And don't forget your camera... pics of him w/ family and friends could be printed and framed as a gift (for closing night!) or for the memory book!
Have fun!