Two-leg and one-leg heel raises - Stand on the floor, next to a table or chair for support. Rise up on the toes of both feet and hold for 2 - 5 seconds. Repeat 10 - 20 times. Do 2 - 3 sets per day and work up to 50 heel raises per set with each leg.
Do the same thing in reverse. Meaning lift your toes of the floor balancing on your heels. This one is harder, at least for me.
Towel gathering exercise - Set the balls of both feet on a towel. Flex the toes to gather the towel under the feet. The heel remains in contact with the floor, and stationary. Progress to doing this exercise 10 times and add a light weight to the towel for added resistance.
Marble pick up - Place a marble, or wadded piece of paper, on the floor. Pick it up with your toes. Repeat 10 - 25 times
There's some good stuff here if you have a thera-band elastic thingy.
http://www.athleticadvisor.com/Injur...in_splints.htm