Is it a trend now? Are frontend developers required to learn design? And if yes, then which books/courses/articles would you suggest?
Do stuff as much as possible and focus on the output, e.g. look for quantity over quality. [0] It's important to have the proper mindset, so you have to learn how to ignore the frustration and how to fight your ego. The paradox here is that if you follow this approach, at the end you start producing more and more quality work.
Deliberately replicate other people's work. With the time you'll start noticing different patterns and trends and build on top of them your own ideas.
[1] Read psychology and have genuine interest in humans - why do we respond to given things, why these things work and experiment with them.
[0] http://www.amazon.com/The-War-Art-Through-Creative/dp/193689... [1] http://getmentalnotes.com/resources
How to get there: just create stuff, start with smaller things (like a simple blog design or even smaller like a page about yourself) and get inspirations from other talented designers. Maybe you just copy their stuff 1:1 in the beginning just to get some feeling for shapes and colors.