It's the most obvious - but naming conventions are so crucial to simpler code, it's crazy that people are so loose with them...
Google publishes a JavaScript style guide. For more guides, please refer to this link: Google JavaScript Style Guide
Here are some key points:
See 13 Noteworthy Points from Google’s JavaScript Style Guide
See chapter 2: Meaningful Names Clean Code: A Handbook of Agile Software Craftsmanship