Here are a few more thoughts/recs that have worked for us:
My DD always has her iPod and headphones with her. This helps to drown out some of the noise/ loud sounds. She is easily overstimulated by certain noises and sounds. There is really no rhyme or reason so the iPod and headphones are a way she has learned to self regulate or if we see her starting to have difficulty we tell her to use her iPod and headphones. She also loves to take pictures with her iPod
My DD is also food sensitive. She is self limiting to what she eats and has allergies so we very rarely book sit down meals. Not only can they be very expensive, but she can't always sit for long periods of time. Although, I will say that if sit down meals work for you, the restaurants are very accommodating regarding allergies, gluten free etc. We tried a character breakfast but it really wasn't worth the expense as she wouldn't eat any of the food. So we leisurely see characters in the parks and that seems to work the best.
I also bring snacks with me in the parks in a a small back pack. Again, mostly because of food allergies and her pickiness.
I prepare her ahead of time. We frequent the Disney site, u-tube etc. to look at rides, the parks, shows etc. so she can visually become comfortable with what to expect. She is very visual so I will print out pictures for her and put them in a binder which she likes.
I ALWAYS take cues from DD at the park. If something is making her uncomfortable then we simply move on. Trying to get her on a ride that she is not feeling good about will ALWAYS not end good! Once a meltdown starts it is very hard to regroup.
Don't expect to see and do everything. Even with the best laid plans and perfect circumstances and No child with autism, there is simply too much to see and do and it can be exhausting when you try to squeeze everything in. We NEVER park hop. We stay in one park per day. What we don't get to on this trip, we will see next time.
Get plenty of rest/sleep.....a tired child is a cranky child......a tired child with autism is cranky quadruplets!
With the GAC you can sit in the handicapped sections for the parades. This gave us a good view and better space around us. I will sit in this section with DD while my DH and boys stay nearby outside of the handicapped section. I appreciate the GAC for her but don't feel that we all need the accommodation so I won't take space away from others simply because the GAC does allow 5 others in your group. The same goes with the rides. I consider the GAC a privilege for her because of her disability. My DH and boys do not need the accommodation.
Hope these thoughts have been helpful. I will add more as I think of them. Pixie Dust to All !!!!!