When a language has some central design principles, you can spot projects that work really well because they go well with that design.
Related Posts
The niche of short, environment-specific scripts, and the consequences for programming language design choices: https://brrt-to-the-future.blogspot.com/2021/03/why-bother-with-scripting.html
I'm a huge fan of Swift's 'Error Handling Rationale' design document: https://github.com/swiftlang/swift/blob/9315673c003875158852579bd1f33480cdec5461/docs/ErrorHandlingRationale.md#fundamentals
It carefully defines terminology and compares with other languages, so you can understand Swift's position and preference in the design space.
For hobby projects, I really like software where I can do small features or tweaks. Sometimes I don't have time for anything more substantial.
Website projects are great for this. Are there other areas?