Sami Keijonen shared his experience as a first-time contributor to WordPress default themes on Post Status. It’s an excellent read, especially if you’re interested in getting involved in WordPress Core or default themes.
Twenty Seventeen wouldn’t be the same without Sami’s work. His experience provides a good example of how to watch an open source community, learn from it, find a niche within it and attack when you see a way to give back. My favorite advice is this:
Once you start contributing, you shouldn’t just disappear with no explanation. If you’re running low on time or have other obligations, it’s totally understandable, but be sure to politely inform others you can’t continue anymore, so they can pick up where you left off.