Documenting Handwriting Progress

In addition to reviewing class work, I've been taking monthly samples of a student's writing.  This customized paper can be generated from the Handwriting Without Tears site, under "A+ Worksheet Maker."  http://www.hwtears.com/hwt/online-tools/APLUS

Each sample is clearly dated and I also write down which words or letters the adult has written.  This may seem silly but it sometimes gets a little hard to figure out what I've written and what the student has written, especially since I try to always write sample text for students with my non-dominant hand.  Students sit to my right and I use my left hand to write the letters so the students can see how the pencil is moving on the paper.

In my opinion, the most important measure of improvement is the student's functional writing in the classroom and on homework.  Writing performed under the direct supervision of a friendly therapist is usually a lot more legible than what the hard-working teacher sees on a daily basis.  Yet, it is good to document what the student's "best" handwriting can look like, since that gives us insight into the factors which influence legibility. 
Do they need extra time to form letters correctly--do they rush through the writing in class so they can move on to something else--do they have a difficult time remembering where they are on the page?  Knowing this information helps us suggest accommodations and strategies to the teachers to aid writing in class.