Sensory play is so important to the brain development of young children.
For our spring theme sensory bin, we just used things we already had around the house.
I used shredded paper “grass” as the base and added in some toy shovels, fake flower petals, a frog figurine, and a fake bird. I also grabbed some plastic eggs and hid little bird and chick erasers inside of them.
My kids were ecstatic when they found the little erasers, and they quite enjoyed transferring the “grass” to another butterfly container that I provided them with.