The [work]book 'American Cursive Handwriting' by Michael Sull (Goodreads Link) is an interesting 'read'. I picked up a copy years ago when I first started getting interested in writing. I was looking for ways to slow down, think and better remember things. After I entered the world of analog writing it quickly became clear it helped me on too many levels to properly enumerate here.
The biggest problem I had early on with analog writing was my legibility and writing speed. I could barely read my own scribbles and anyone else had about zero chance of reading my handwriting. Despite other gains I had with analog writing, these were major hurdles for me. I would definitely have thrown in the towel on analog writing if I hadn't found 'American Cursive Handwriting' during my research into ways of improving legibility and speed.
During my research on legibility and writing speed I discovered cursive is still 'a thing' and can help with writing speed and can also help make fountain pens, rollerball pens and more a delight to write with.
More research and digging turned up 'American Cursive Handwriting' and some deeper research let me find a copy for sale.
To say this book changed my writing for the better and added to my love of analog writing is understatement. It's well thought out, organized and sets up the student (reader) for success at every level. It assumes a basic writing skill (fine for adults, be mindful with children under 12 or so).
You start out with basic exercises and over time they build into much more complicated ones that will feel like full pieces of writing. The book is a great execution of 'practice makes better' and has a self teaching component which lets the student choose their pace. Be careful on pace, too fast and you'll get terrible hand cramps, too slow and you're liable to forget the lessons. A lesson or two per day was the pace I used to great success.
The drills, light history and my desire to be proficient with analog writing was a perfect blend to get me through the entire workbook and recommend it to anyone interested in learning cursive or building up their cursive handwriting skills.
I recommend a fine or extra fine pen for the exercise as well as a thing sheet of paper (or copies of the original pages) for the drills and exercises. By not using the original pages you can go back later for more practice or pass the book on to the next up and coming analog writer.
I should also point out that it takes at least 3 months to get through all of the exercises and more like 6 months if you take a more measured pace. This is a book you commit to. A Good Thing™ in my opinion.
It too me just over 4 months to finish and I can now write legible cursive down to 1/16 of an inch high (inside a 5mm rule comfortably for those with good paper and/or notebooks).
If you want to improve your handwriting via cursive, seriously consider this workbook.