Good looking UI?

Currently I am working on a desktop PC app that makes your PC feel more like a console - mainly for me and my girlfriend (will release on GitHub once I feel like it’s ready). I feel like the UI looks like straight out of codex. Literally my second time using it. So I am wondering - what skills / tricks do you use to get a beautiful looking premium UI? Reference pictures of what your vibe coded Desktop app UI looks like would be nice 👍🏻