While it is possible to help children improve their fine motor skills, that's not always the problem. Quite often gifted children simply think faster than they can write. When they try to write fast enough to keep up with their brains, their handwriting suffers. So what do you do? The best solution is to help your child learn keyboarding. Kids can learn to type fast enough to keep up with their thoughts and what they write will be legible. Understanding teachers will often allow young gifted children to do their work on a computer.
You may worry that little Johnny or Susie will never learn to write neatly if they always write using a computer. That may be true, but chances are their minds will never slow down enough to do the kind of writing practice that leads to neat handwriting.