I am a huge fan of using playdough. You can read HERE how I like using playdough to improve fine motor skills with my own children.
Did you know that you can use playdough to reinforce math skills and literacy skills, too? I recently found a couple of sites that offer playdough mats for FREE- Yessirree! I am printing several off right now for my younger kids (on cardstock and then I will laminate them or use contact paper to cover them).
Planet of the Apels has a very thorough post on how to use these mats and lots of cute mats to download.
Sparklebox has tons of topics and teaching skills you can choose from.