[diveintothe9]

I'm a UX designer, and by no means a pro, but my workflow is usually along the lines of:

- wireframe on Sketch (some people are faster on paper, I'm faster on Sketch/XD/whatever)

- create what I call a medium-fidelity mockup (basic styling, all components, etc, but not much actual content)

- create a small PWA/webpage to demonstrate behavior and flow

- go back and complete my high-fidelity design

- send it, and any styleguides, to the devs

Throughout these steps there are multiple rounds of iteration, review, and branching, but eventually you have a product design ready to go.