EmulationStation is where I have spent most of my time making themes. Not because I think it is the best front end or anything, I just got comfortable and understood the xml (not my strongest skill for sure). I enjoy creating and because I do not enjoy spending time researching and learning, I focused on making themes in what I knew best.
I have made and shared with the community around 1300 Themes for ES. All of the themes I akee are available in my Theme Installer Script. Or you can grab themes one at a time and add them manually to your Pi build. Almost all my themes have been created for a 16:9 horizontal monitor. I see people using my 16:9 themes on 5:4 or 4:3 monitors all the time and it looks terrible in my opinion. If you like a theme in particular and need it in another screen ratio, send me a message and I will see what I can do.
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