A strategy that's helped me:
After you've decided what topic you want learn follow these steps.
1. Quickly familiarize yourself with the topic. I usually watch a quick video on the topic (<10min). This helps you familiarize yourself with terminology, concepts, and why it's important to learn.
2. Next find a cheatsheet. Print it out if you can or grab a notebook. You want something that's already done some of the leg work for you. If you can't find a cheatsheet, go back through the tutorial video and in a notebook, write out concepts they mention, leave some space between them, you'll fill in details later.
3. Follow along to more in depth guide. Be it a tutorial video, course, written document. When going through your course, in your cheatsheet or notebook fill in concepts that you've missed and add short notes to your cheatsheet. This will help you learn more because you'll memorize concepts as you write notes along with it. Don't rush and after you've written something out, close your eyes and actively try to recall what you've written. Active recall is one of the best methods for memorization. Also, these cheatsheets can sit on your desk and you can reference them when you begin to code something in the language you've just learned.
I've been following the advice of James Altucher to write ten new ideas a day. Since I'm a junior developer I decided to make a small web app to save my list of ideas. Let me know what you guys think :)