Yes, I would practice as bad habits are difficult to break....the books are called "Handwriting today " by Andrew Brodie.There are a few workbooks.It aims to improve your handwriting whether you are 8 or 80 !!
The first book also covers how to correctly hold a pencil and the techniques for joining letters etc which sometimes can be the problem.It goes on to show you how to write the first joining letters, to tall letters and for letters like s or r which my son always managed to look like a k ! They are in little sections, so although a bit boring, you only have to do a little at a time.
Now my ds is going to secondary, he is taking greater care with his writing as he did say he thought his looked a bit " babyish " !! Bear in mind though, younger children often have scruffy writing etc as they spend more energy getting their many thoughts down on paper...which I think is more important.Even though my ds was always pulled up on his writing, he was often praised for the imaginative content and I would rather it was that way round !