I start by finding and assessing tutorials based on amount of content and hopefully there's at least one tutorial that seems to cover a lot of bases and also isn't too handwavy. Then I follow along, writing everything out by hand. All the while, testing various tweaks and changes. (Make sure you've installed idiomatic/popular tools and use them right away to really get acclimated to the language's workflow)
After I'm done with the tutorial, I first take a look through the language reference and read various bits and pieces, searching the internet for anything that seems interesting/vague to find more thorough explanations.
Finally, I pick a small project to complete in the language. At this point you want to try writing most everything on your own, but don't be afraid to find a similar project and try and apply patterns/implementations in your own code. Often times this is the best way to see how others code in the language.
One thing to note through all of these steps: just as with a human language, you need to immerse yourself in it! Discuss on IRC channels, get active in forums, contribute to open-source repos, find various ways to connect with others. You'll find that people will more readily help you if you are giving back to the community.