I've just skated through the last few pages, and I thought of a few things we did 2 years ago for DD's "Pizza and cupcakes" party. (Was supposed to be in a kids cookery school but teacher illness there forced it home with less than 24 hours notice).
Party bags each had a wooden spoon and a different shaped cookie cutter, with some jellies and any prizes (DSis had got those as freebies at the Young Scientist's exhibition that morning where she was minding a stand).
I got all the kids (12 of them!!) to bring aprons if they had them, and I had a couple at home that I could share, a few kids had to use my adult ones tied up to fit them.
I bought readymade bases, pizza sauce, a few bags of grated cheese, and different toppings. We helped each child put on sauce, they decided the cheese for themselves and then went wild (or not) with toppings. (Small size bases would be better but I couldn't get those, so cut full sized ones in half). The middle of the table had bowls of grated cheese, chopped ham, chopped chicken, pepperoni, sliced mushrooms, sweetcorn, diced peppers, and tomato. (It was mostly ham, pepperoni and mushrooms used, but some were more adventurous). I knew 1 person didn't eat pizza so had a tray of chicken nuggets - more nuggets and some oven chips would have been useful. While they played "Pass the parcel" in the sitting room, we cleared the table and baked pizzas. After eating those, the nuggets, drinking jugs of squash and following them with crisps, popcorn and sweets, DSis had arrived and took them onto the green outside and played "girl guide" games (different running games I recognised from guiding days). We cleared the table (I had layered 2 plastic cloths so pulled one at that stage) and set out the 4 dozen buns I had baked, 3 different coloured icings in bowls, and about 10 different small bowls of sprinkles, edible glitter, chocolate stars, etc , and 10 tubes of writing icing (I had these ready on a tray to put onto table). The kids came back in, and went wild decorating. I had plastic plates (strong-ish) to put the results on, and we did the cake just as parents were arriving. It meant that the later parents found their DCs still engrossed in perfecting their buns, and all the results went home with them. So while I was not impressed at the cookery place pulling out, it all went ok in the end.
I had done a "Fairy" party the previous year, with a girl coming to entertain for an hour (knew the theme and adjusted her games to it) and suggested the guests could dress as fairies (which really meant a lot of Disney princesses, but there were some fairy wings too). For that, I made sandwiches which I cut with a star cookie cutter, rocky road crumbled in chunks on a plate as "edible earth", with mushrooms sticking out of it (I think they were made of buns with red icing and white dots), butterfly buns, and I can't remember the rest of the food. The squash was "Magic fairy juice" (I think I put some chopped pieces of fruit into it), we got a fairy themed cake in M&S, and I do remember having "Pin the star on the Wand" as a game afterwards and DH doing a "Musical chairs" as parents arrived.