Ask HN: How to Become Better at UI Design as a Software Engineer?

I'm pretty good at modeling data, doing heavy back-end coding, and even working with JavaScript, HTML, and CSS. I'd like to get better at actually designing interfaces and general web design layouts.

I can take an existing html bootstrap template and slice it up into partials and make things work with Angular or jQuery, or even good old server side template rendering. I want to take my skills further and be able to come up with unique designs for web applications.

Can anyone provide good resources or a starting point to become a good UI Designer?