I have a 160 DPI screen so everything is very small by default. Xfce's themes are already smallish on normal screens so on mine, they are absurdly tiny. None of the themes were useable so I created my own.

I took the standard Tgc theme and doubled the size of everything, then cleaned up the diagonal lines and shadows. I changed the shade icon to match modern Xfce but other than that everything looks identical to Tgc, just twice as big. I used a text editor for everything so the theme will change colors properly based on the current appearance theme.

This will look absolutely ridiculous on a standard-resolution screen. It's intended for only very high-DPI screens, such as a Retina Macbook Pro, a PC laptop with a full 1080p 14" screen, or a tablet designed for a high-DPI OS like Android. I recommend using it with a font DPI of 144, as shown in the screenshot. Download it at:

http://frammish.org/Tgc-huge.tgz