So, if you want to contribute to open-source — as a whole — here are my tips:

• Find problems which you are intrinsically motivated to work on.
• Focus on developing skills to get up to speed on new codebases fast.
• Don’t be afraid to work on any project — new languages, tools, libraries; learn enough of them and it’ll only get easier to learn more.
• When you file bug reports with a FOSS project, get into the habit of following up with a patch which addresses the problem.
• Get used to introducing yourself to maintainers and talking through the code; it always pays to ask.