Triple Triad Custom Card stuffs.
Using the Magic Wand for removing white space is baaaaaaad. Leaves a nice jagged edge - for better results, zoom in and use the Polyganol/Magnetic Lasso to get right to the border. Takes longer, but looks better overall.
And as for making full decks, I've started a few, but mostly with custom templates. I tend to be pretty bad with graphics, though, so they're not really great.
I guess I might as well link to some of them here, though, so
here they are.
(As for what I was saying about using the Magic Wand, look at the edge of the Black Frost or Lilith images. Those pretty clearly show what I mean about leaving that horrible white border. As for ones done with the lasso tools, look at Yurlungur or Mada. Most of those were Magic Wand-ed through laziness, so have the white edge. Which is probably why I've never got round to finishing a deck - too lazy, not as good as other card artists, etc. ;o