I have a 504 plan that we created for my son when he was first diagnosed (1st grade). I'd be happy to email you a copy. I used advice from this list and others. Send me an email at email@example.com and I'll send it to you.
Our rule is he only eats food from our house AND pre-packaged foods that say "gluten free" clearly on the label. And even then, his teacher (or party host) will remove his serving first and keep it separate.
We learned our lesson at camp when the "I-know-about-celiac-because-my-roommate-in-college-had-it" head counselor told him he could eat the graham crackers because she checked the ingredients and "gluten" was not listed. (Wheat was the first ingredient, but she was looking for the word "gluten")
After that (missed a week of summer camp) we don't rely on others to be able to figure it out. It is not always easy - it took me a while to learn it all. Now, at age 9 he can check for himself, so it has gotten easier.