I used to work for High 5 Games, a developer of slot games content.  I was responsible for all the artwork except for the painted portraits of the character's faces.  I created all the frames, logos, symbols, background art, and any other UI elements seen below. 

Some years ago, a gaming community website asked me to create web skins for them.  I was asked to use the artwork and logos from fan kits and/or the game's official website. And, with a couple of exceptions here and there,  I had to build the actual frames, buttons, hover states, and clicked states from scratch, matching the existing aesthetic and page format.  

The below are just a few UI tidbits from random projects.  Some are incomplete due to the projects being cancelled.