Designers and front-end developers always share a critical partnership because they may complement and sometimes contradict each other.(P.S. Same thing cannot be said for relationship between developers and testers ;p ). As a front-end developer I have daily interaction with designing team and consequently I can get their help in designing even for my personal projects. I have gone through the same situation and even tried to learn designing myself but failed miserably because of lack of time and creativity.
Although I feel like I can become better at designing I don't give it a try now simply because I feel it's better to be proficient at one thing(programming) rather than trying to be good at everything.
I met most of my designer friends at college when we were in working together for technical events in college and luckily we are still in constant touch. My other contacts are from designing team in my office who handle designing part in professional projects. Coding meetups and workshops are also good places to meet people from other backgrounds.
To cut long story short a project's success depends on people with different skill sets like coding,designing,testing and even management. Building contacts and having constant interaction with every one of them keeping your own ego aside is a critical aspect of working in any domain in technical industry.