Create a separate project for Web Controls

I have a few web form applications which I copied and pasted some user controls to each app. Now every app has the same controls, but each one slightly different because I made small changes/updates to the controls.

I want to move all the controls into a separate "common project", and then from other projects reference the controls.
I can't find a suitable project template (when I create a new project in VS 2022) for web controls.
How do I reference in my apps the controls in the controls project? Also, how do I reference files like CSS or JS ?

Is there an example online?