Water can be easiest, and most simple sensory play for kids. The best part is, it seems to be one of the favorites for kiddos. Just add water is my motto. Last night I needed to make dinner and read through Kailyn's school papers. Kailyn was in her playroom needing/wanting some alone time, and Colton was demanding my attention. So I pulled out the Tupperware tubs, filled it up with some warm water, threw in a few sponges, viola...Colton was beyond happy.
Well of course big sister heard how much fun he was having, so then water play turned into a party of two. Another tub was added, more sponges thrown in, the clothes even came off. Both kids took turns sitting inside the tubs pouring and playing with the water. I would have to say that evening water play was a success. Try it with your kids. I guarantee you they will LOVE it.
As a side note, the towels were down to protect the kids from slipping on the wet tile floor, not because I didn't want them to make a "mess". Messy play does not bother this mama. Daddy on the other hand....well we are working on it.