I always loved T.Kings work, and especially his Spell Icons..
I played with the idea of having the background of the Icons invisible, and as I couldn't really find anyone premade, I dug out my own favorite T.Kings G2 Icons and made the backgrounds transparent.
At first I had the spell/buff background color, all cleared, but that made it virtually impossible to distinguish detrimental effects from beneficial..
So I added a red line at the bottom of detrimental effects.
I use my horse a lot, and the typical boot icon seemed out of place, so I put in a Horseshoe of flowers
for that Icon instead..
/edit
Added gems for spellbar, transparent too