I agree albeit in my opinion UI design is mostly a craft you can learn and a small part an art where you rely on your talent. I have approached several projects with making a matrix (Excel-Sheet). The rows are the list of UI-screen. The columns are the criteria I consider necessary for a good UI:
- Usual UI conventions (Mouse for look, WASD for movement etc.)
- Appropriate aesthetics for the game setting (e.g. no baroque font for a Scifi game)
- Same colors, fonts, button styles, and icons across every screen
- Minimalist design, as little text as possible (except for credits and story)
- Visual hierarchy (e.g. Play button bigger and more central than e.g. audio volume)
- Readability including different screen sizes
- Immediate feedback (wait cursor if necessary)
- Screen shows where I am (e.g. by headline/picture/background)
- Screen easy to find/open and easy to exit
In the matrix I mark every box whether I think the criterium in the column is met for the specific screen (I use a plus for good and a minus for bad) and fix what's bad.
Those criteria don't replace play-testing. It's more like a check if the UI is ready for play-testing. Typically I'd do some fine-tuning according to the feedback from play-testing.