In a world of bootstrap, foundation, pure, topcoat, etc., designers are falling into a pattern – reusing the same ole' patterns for every project. You're solving a unique problem and you need a unique solution.
Rolling your own design system can help you solve problems, make decisions, retain consistency, and create a meaningful and recognizable experience for your users. Follow along as I explain the rationale, process, tools, and techniques that go into creating a deliverable and documented design system – be it from scratch or derived from an existing product.
BEM: http://csswizardry.com/2013/01/mindbemding-getting-your-head-round-bem-syntax/
OOCSS: http://www.stubbornella.org/content/2009/03/23/object-oriented-css-video-on-ydn/
Scales: https://github.com/yodasw16/scales
Inuit: https://github.com/csswizardry/inuit.css
uncss: http://davidwalsh.name/uncss
csso: http://css.github.io/csso/
gzip: http://www.fiftyfoureleven.com/weblog/web-development/css/the-definitive-css-gzip-method
yelp: http://www.yelp.com/styleguide
trulia: http://trulia.github.io/hologram-example/base_css.html
github: https://github.com/styleguide/css
style guide guide: http://vinspee.me/style-guide-guide/
interface inventory: http://bradfrostweb.com/blog/post/interface-inventory/