Play-doh is great for fine motor, they can roll, squish, pull it apart and cut it.
Also have them lay on their belly when coloring, this makes them use their hand, not arm to color making stronger hands/fingers.
Picking up small dots (hole punch some and "make a mess" have them help pick them up one at a time)
I know there is much more... can't think right now.
My son is what the preschool teachers call borderline with his fine motor and these are a few things that they told me to work on with him.
Also you can get clay that is somewhat stiffer than play-doh to work with. If I think of others, I will add them!