Gather up your materials
Cut the card stock to the size you want for your card. I originally cut an 8.5"x11" in half, but later cut it again (when I ran out of foam circles... jejeje)
Fold it in half
Go crazy on the foam sheets with the paper punches. I have four different sizes, and used the biggest and the second to smallest, because the difference in sizes let you see both colors clearly when you glue one on top of the other.
The mound of foam circles...
I glued the smaller ones onto the bigger ones, using tweezers. I put some glue on a scrap piece of paper, dipped the small circles in it, lightly and then positioned them on the larger ones. This takes time and patience; it also helps if you have an obsession with large amounts of small things.
Once the circles-on-circles dry (I let them sit overnight, just because it was late) you can start to glue them to the cardstock. I also did the tweezer and glue on spare paper thing, to keep my hands clean.
I didn't use any pattern, just tried not to repeat the same color above/below or beside itself.
Take a break and get yourself a snack
When you're done with the card or run out of foam circles or patience, trim off any excess cardstock, and let dry.
Add your message to the inside and send to someone who will appreciate your hard work =)