If you're looking to improve your Spencerian specifically, I'd definitely recommend getting the theory and practice books, for one. They're super helpful.
In addition, I would recommend using guidelines, since your text seems to meander up and down, as mine does when I don't have them. You'll eventually get to the point where you don't need them, but having that guide at the beginning is one of the most helpful things. (The Handwriting Repair link in the sidebar is a nice source to demonstrate the usefulness of guidelines.)
Really, the best advice I can give you is slow down. Focus on how the characters are supposed to look, and your technique in general. Speed will come later. It'll be incredibly aggravating (trust me, I know), but you've gotta start slow.
Hopefully that was helpful.
Spencerian Penmanship https://www.amazon.com/dp/088062096X?ref=ppx_pop_mob_ap_share
Get to it!
Not OP, but (from what I've seen) the definitive resource for Spencerian handwriting is the original books by Spencer himself. They're what I'm using, and by the sounds of it, what OP used too.
It's a nice looking font. If you'd like to improve it, as others are saying, get a good stable fountain pen, and this, you won't regret it.
I’ve been slowly making my way through these . Which, after looking up Michael Sull, makes sense.. He has incredible credentials. And I saw that he’s heading up a penmanship school! I now have something to look into, since I’ve been wanting to work with an actual person for awhile.
As someone mentioned below, it’s “Spencerian” (it quotes because I’m still working on it, so some of the letters are not formed properly yet).
I especially haven’t learned all the capital letters yet, but here’s what I’ve got.
This is the book I’ve slowly been working my way through.
Nice I've been personally practicing with these workbooks that focus on spencerian