I needed something to keep A busy while J and I did school the other day so I whipped up a quick sensory bin for him. I have a couple of empty plastic bins I keep around (perfect for sensory bins and messy play). I set one up and threw in some black beans, split peas, and oatmeal.
When we're done with a sensory bin I toss the filler into a gallon Ziploc bag so we can use it again later, and not waste it.
I threw in some wooden blocks and a few random tractors and construction vehicles.