The Fourth of July is a fun theme for sensory play, but these ideas can be used any time of year and often done with different colors for different seasons if you like.
This red, white and blue water play bin from Simple Fun for Kids is super easy to set up (and you could do it in the bathtub when kids need a cool down).
No sensory list is complete without slime, and 24 Hour Family has a good simple recipe for red, white and blue slime. Crafts by Amanda has another slime recipe that’s full of glitter and stars if you’re into those sorts of things.
My daughter loved cloud dough when she was little, and this patriotic twist on it from Glitter on a Dime is another fun way to use it. Also check out their patriotic potions, another easy project you can do throughout the year.