I always wanted more options for the subtabs in DS (at least border options). I finally got around to playing around with mine and figured I'd share.
This is what my subtabs looked like before (boring):
Here's some tweaks to give your subtabs some borders, background images and sliding animation (text file). Add it to your Advanced / Custom CSS.
Use what you want out of it. I suggest you use a small pic & optimize it to keep the size down for response times.
I threw together some background images & optimized them. Here's a new example of mine.
Save the image you want and upload it to your own site. They are the same colors as the Floating Quick Navigation If you are using that too.