Google children's bucket hats and you'll find a variety of free or cheap patterns. I made the boys matching bucket hats for the 4th. I made Ali another ruffle skirt using the Marie-Madeline Studio pattern I bought a year ago.
Doing sparklers on the deck. Fireworks are legal all day on the 4th in our town.
The firetrucks spray down the crowd at the end of the parade. My kids always hide...not yet to the age where it is a delight!