This is how I write without thinking about it. My handwriting is somewhat difficult to read at best. The letter sizes are inconsistent, same letters are made in different ways, such as lowercase y sometimes looping and sometimes straight. It is not straight across, and does not stay on the same margin each line. The spacing between letters and words is inconsistent. The slower I write, the more "wiggly" the lines get. I've been writing with my arm for the last year instead of my fingers, but it really seems to have degraded my handwriting instead of improving it.
I have attached, next, the sample text which someone wrote and posted on Reddit. It is so consistent and clean, anyone could read it. The letters are consistent size and there are no shaky lines.
I hope there is some way this class can help. I know my grip is the first issue, but the video did not address it very well, as the positions listed are painful to me.