This party idea will work for just about any age 3 and over. Kaiden doesnt really know kids his age so all of the guests were over the age of 5. We had 15 guests in addition to my 2 kids so there were 17 kids total and the party took about 2 hours.
First things first
Choose a location, date, and time. Then make up some invites. We did ours message in a bottle style. We saved up some of those small gatorade bottles and cleaned them out. I made the invites on Photoshop and printed them 3 to a page. Cut them out, loosly roll them and slide them into the bottle. They fill out the bottle almost perfectly. I've attached the psd file so you can just change the info if you want to use ours.
When you know how many kids will be there, start making gift boxes. I made Scooby Snacks boxes for each guest. You will need:
Cereal boxes (one for each kid)
paint and brushes
1. Break down each box so its flat(see photo)
2. flip over to plain side
3. hotglue back together along the original seams
4. draw out the layout of the scooby snack box design
5. Paint them
6. outline in sharpie
We put all these scooby snack boxes in a larger box and carried them from game to game so the kids could put their prizes in them.