Artist Trading Cards are little works of art. The only true rule is that your finished product has to be 3-1/2"x2-1/2". ATCS are a great change from making greeting cards.
All Sewn Up Swap
Chocolate Swap
Coffee Swap
Treasure Hunt Swap - Had to use specific items when creating an ATC
Alphabet Swap - Letters E-N-W
Alphabet Swap - Letters H-Q-L
Alphabet Swap - Letter J
Let It Be Free Swap - Everything used to create the ATC had to be "free"
Moon/Sun ATC
Orange Swap
Lavender/Orange/Neon Green Swap
Valentine ATCS