First, take a regular card base and cut the front at a diagonal.
Flip the cut off piece over and glue to the other flap. I usually paste mine to the inside so that the bottom of the card is sealed by the fold. (Does that make sense)
Here is another view. Don't forget to use those pattened papers.
Then, just seal on the sides only. This will form a pocket and allow for the card part to be inserted.
Like I said this is a great PAPER SAVER. Cheap way to make an expenseive looking card.
http://www.youtube.com/watch?v=6upODac5TL4