I'm going to show you the steps on how I create my Kawaii Note Cards, separating them into 2 parts.
First is the design stage.
Since the note cards are rectangle-ish shape, the face and body will have to be in one block. That leaves the creativity for ears and tails. I draw quick sketches with pen and paper, nothing fancy.
Then moving on to illustrator. Open a new horizontal letter size canvas. I use illustrator mainly because it's a great vector program to create sharp lines and shapes, I like to tweak around using the lasso, pen and selection tool, be warned...this part can be hideous sometime.
Just keep building the shape and adding couple more details.
After the front side is finished, I made two other copies placing next to each other.
The back side is much simpler, depending on how complicated I want the "writing" side to be, usually couple of lines will do just fine. The back side will be a separate file, but because we don't want any design on the back to be cut off, have a front side design on top of it as guide.
And now we are ready to print and cut!