I've always found that one of the best ways to learn something new is to get my hands dirty and start writing code. But it also helps me to have a project to work on, and a goal in mind. You could always go the traditional route and build a to-do list. I need something that's going to hold my attention a bit longer though. With that in mind, here are a couple of ideas that have inspired me recently.

Hot JAMS(tack): Building a Music Discovery App with Drupal and React
Brian Perry gave a talk at DrupalCon Nashville about how he created an application for visualizing trends in popular music using Drupal and React. It's an interesting example, and I love how he's taken something he's passionate about and turned it into a learning opportunity. Find something to play with in this huge list of publicly available APIs.

Thanks to Joe Shindelar and the folks at Lullabot Education for the nice shout out in the React for Drupal newsletter. Here's to hoping this project continues to be useful for people.