Here is an aperture card that I designed in Inkscape, and cut out in SCAL on my Cricut machine. At first I made a simple aperture with initials (white card). After having the card sit on my desk for a day, I got to thinking that I could 'dress-it-up' a bit and come up with another version (pink card).
I designed some swirls to go around the outside of the aperture. A 'Swirl' CRI-Kit gel pen was used to draw the swirls.
Then I used the 'shadow' function in SCAL2 and cut the swirls out. I also used some foam dots to raise up the design. Some overhead transperency film was used behind the initials to make it less flimsy, and give it a more finished look.
If you would like to learn how to make an aperture card -- check out this tutorial by Dan (Aperture Card). I have to say that I am always impressed by Dan's creations, and I love his tutorials (especially his cool English accent).