Stamping With Roxy gave me a couple ideas for this card. However, I was able to use half the paper, which when you make a ton of these bad boys, you can save a lot of money.
cut your cardstock as usual using a half sheet of 8 1/2 x 11 paper
fold like you're making a regular landscaped card
hold it with the fold at the bottom
cut a diagonal line (you can use your cutter once you figure it out, but I want you to visualize what is being cut) that runs from the top left hand corner of the "front" of the card down to the bottom right hand corner. This will cut off a triangle.
flip the loose triangle upside down (so the 90% angle is at the bottom) and slide it in place on the right hand side of the card
glue the far right and far left sides of the card (you don't need to glue the bottom of the triangle down because it is now resting in the fold and you don't want glue getting in the way of your insert.
create an insert and embellish as usual
(Directions and pictures from Splitcoast)