I don't think there is an age limit! I think sensory play is fabulous! I really should be doing more of it with the kids. We just got a water table for DS's birthday so I am excited to set that up. DD used to love our rice, beans and pasta bin and also enjoys shaving cream in the tub and the sandbox, of course!
Sensory stuff is great for developing handwriting as well. Our OT where I used to work would have kids do a lot of sensory things to have an extra sense of feeling what they needed to do to formulate letters....trace with their fingers over sandpaper, use a pencil on paper over top of screen material, popping the air filled bubbles that come inside of shipping packages, etc.
I should let her finger paint and all of that!
Come back and share your "ton of ideas"!!!!!!!!