This seems to be a common problem and some suggestions have been: use a fountain pen, slow down, and take a penmanship course.
Fountain pen- check!
|My reward for a good show for inviting!|
Penmanship courses/books- there are some online, and also books (luckily not all are designed for children- many are just for improving what we already know.)
|Theory + practice books|
|Bought this in England in 1999. Available here|
|Available here, and for Kindle.|