Polymer 1.0: UX User Authentication (Best Practices, Guides & Examples)?

Is there a "Polymer" way to authenticate a user?

This question includes both the technical parts and the UX.

A nut-soup example (and / or tutorial) UX for an auth user would be fantastic.

Note. The Polymer Starter Kit does not include examples of UX authentication.

In this question ...

"UX" means:

The FULL "user experience" involved in registering a new account, logging in, and handling forgotten user ID or password. For example, a typical landing page for a typical web application usually has some buttons in the upper right corner for registering a new account and logging in. What happens when someone clicks on those buttons and how to handle the entire flow would be a very useful example for Polymer developers considering the functionality is required for most modern web applications. I would really like not to create my own amateur "home-w610" mix from scratch for a solution, but instead have something relatively professional and versatile, I can "plug n-play" into my app and only change if / when necessity.