@kmakm you can get therapy dough for about $15 and it comes in different strengths. The strength thing was important because initially he could barely do any of them. My son had this to help with his grip and fine motor skills and I can remember the exercises he did still as well. Things like rolling it into a snake and then making that into a snail. Making a volcano was another one. The killer exercise was to get a a small ball of dough and using his thumb roll it up and down each finger
http://www.thetherapystore.com.au/product/theraputty/