Use a fountain pen. You can't press too hard: it bends and breaks the nib.

Disposable ones are good enough now, e.g. the Pilot V-Pen.

https://cultpens.com/products/pilot-vpen-v4-disposable-fount...

Fountain pens are nice too since you don't need any pressure.

My writing looks a lot better if I just force myself to slow down and be deliberate, but honestly it's a constant battle. I'd definitely benefit from practicing penmanship on it's own.

I've had many writing classes in school and different holders for the pen etc but I never managed to improve at all. Writing is just not for everyone.