On winter days when it's too cold to get outside I give the boys a sensory box to play with. Yesterday we had crazy cold winds, so I put together a construction sensory box for them. I mixed decorative gravel with some old instant coffee I found in the cupboard. The result is the perfect construction site!
Don't be afraid of the mess!! A little tip - I do the messy sensory activities on vacuum day. That way I am really motivated to get my vacuuming done ; )
Other things I use often for sensory activities are rice, water, cotton balls, and beans/lentils.