The Fool is brilliantly executed, wouldn't change a thing. It has a nice balance between the hard and soft edges and the mixture of color and pattern give the card energy.
The border is distracting on the 5 of cups. Maybe neutralize the blue/green a bit or go for a different shade of the same combination. Right now the picture/subject and the border seem to be working independantly of one another instead of working together.
The King of Swords could use a little more contrast, maybe just a little more attention on the edges... they are all soft. A few defined edges here and there wouldn't hurt.
Overall, love the colors and the compositions. Very pleasant to the eye, can't wait to see more.